With opinions having such a decided tendency to materialism, it is not surprising that Lamarck seldom makes allusion to a Deity, and when he does so, he nearly confines himself to the bare acknowledgment of his existence. In his earlier works, there is no mention made of a Supreme Being whatever; and even when his existence is admitted, He is divested of the attributes which belong to him. The glory of forming the works of creation, in which His beneficence and power are so signally manifested, is ascribed to nature, or a certain order of things. This power to which the Deity has delegated his prerogatives, and which he has appointed his vicegerent, Lamarck defines as “An order of things composed of objects independent of matter, which are determined by the observation of bodies, and the whole amount of which constitutes a power, unalterable in its essence, governed in all its acts, and constantly acting upon all the parts of the physical universe[14].” This blind power, which acts necessarily, has not, indeed, called matter into existence, but it has formed all bodies of which matter is essentially the base; and as it exercises no power except on the latter, which it modifies and changes in every possible manner, producing all its various aggregates and combinations, we may be assured that it is it which has made all bodies such as we now behold them, and that it is Nature which confers on some their properties, and on others the faculties which they exercise[15]. All this power Lamarck distinctly admits has been delegated to Nature by the Deity, and among other errors which he conceives to have attached to the ideas which have been entertained regarding Nature, he refutes the notion that Nature is the Deity himself. “Strange occurrence! that the watch should have been confounded with its maker, the work with its author. Assuredly this idea is illogical and unfit to be maintained. The power which has created Nature, has, without doubt, no limits, cannot be restricted in its will or made subject to others, and is independent of all law. It alone can change Nature and her laws, and even annihilate them; and although we have no positive knowledge of this great object, the idea which we thus form of the Almighty Power, is at least the most suitable for man to entertain of the Divinity, when he can raise his thoughts to the contemplation of him. If Nature were an intelligence, it could exercise volition, and change its laws, or rather there could be no law. Finally, if Nature were God, its will would be independent, its acts unconstrained; but this is not the case; it is, on the contrary, continually subject to constant laws, over which it has no power: it hence follows, that although its means are infinitely diversified and inexhaustible, it acts always in the same manner in the same circumstances, without the power of acting otherwise[16].”

While thus admitting the existence of the Deity, any direct interference in the affairs of the universe is wholly denied to him. His sovereignty is reduced to a mere nominal supremacy, as he is supposed to take no care or thought for the worlds which he authorized or permitted to be created, and can have no sympathy for the creatures which inhabit them. As with La Place, and so many other philosophers of the French school, every thing is ascribed to secondary causes, which are made to usurp the place and attributes of the Divinity. Lamarck’s deity, therefore, is the exact counterpart of the god of Epicurus, whose being is allowed seemingly more for the purpose of giving consistency to a theory, or a compliance with generally received opinions, than from any urgent conviction of his reality; and we may justly apply to him what was said of the Grecian philosopher; Re tollit, oratione relinquit Deum.

It has been already mentioned, that Lamarck’s attention was early directed to meteorology, and it seems long to have continued to form one of his most favourite studies. So comparatively limited is our positive knowledge of atmospheric phenomena, that a careful investigation of them afforded the prospect of new and important discoveries; while the endless variety of appearances which they present, and the complicated influences which operate in producing them, offered a wide and interesting field for the exercise of that speculative kind of inquiry which Lamarck loved to indulge. With his usual facility in such matters, he was not long in advancing a theory, according to which the atmosphere is regarded as resembling the sea, having a surface, waves, and storms; it ought, likewise, to have a flux and reflux, for the moon ought to exercise the same influence upon it that it does on the ocean. In the temperate and frigid zones, therefore, the wind, which is only the tide of the atmosphere, must depend greatly on the declination of the moon; it ought to blow towards the pole that is nearest to it, and advancing in that direction only, in order to reach every place, traversing dry countries or extensive seas, it ought then to render the sky serene or stormy. If the influence of the moon on the weather is denied, it is only that it may be referred to its phases; but its position in the ecliptic is regarded as affording probabilities much nearer the truth[17].

So convinced was Lamarck of the accuracy and value of his theory, that he resolved on reducing it to practice, and thus at the same time establish its truth, and attract the attention of the public towards it. For this purpose he drew up a series of almanacks, which he had the perseverance to publish for ten consecutive years, the nature of which will be best understood from the title of that which first appeared. “Annual Meteorology for the Year VIII of the Republic (1800, A. D.), containing an Exposition of the Probabilities acquired by a long Series of Observations on the State of the Weather, and Variations of the Atmosphere, in different Seasons of the Year; an Indication of the Times when it may be expected to be fine Weather, or Rain, Storms and Tempests, Frosts, &c.: finally, an Enumeration, according to Probabilities, of the Times favourable for Fêtes, Journeys, Voyages, Harvest, and other Undertakings, in which it is of Importance not to be interrupted by the Weather; with simple and concise Directions regarding these new Measures.” His predictions, as might have been expected, proved more frequently erroneous than otherwise, but this circumstance was far from inducing him to discontinue his exertions. Every year he had recourse to some new consideration,—such as the phases, the apogee and perigee of the moon, and the relative position of the sun, to account for his previous failure, and afford greater certainty in his future prognostications. After every expedient had been tried without success, he was at last obliged to renounce the labour as fruitless, satisfied that, however important it would be to foresee the state of the weather, it depends on causes far too remote and complex to be made the subject of calculation.

Speculations of an analogous character regarding the formation of the globe and the changes which it has undergone, were laid before the public, in 1802, in a work entitled “Hydrogeology, or Researches on the Influence exerted by Water on the Surface of the terrestrial Globe,” &c. &c. His opinions rest on the assumption that all composite minerals are the remains of living beings. According to him, the seas are continually hollowing out their bed in consequence of being unceasingly agitated by the tides, produced by the action of the moon; in proportion as the bed deepens in the crust of the earth, it necessarily follows that their level lowers, and their surface diminishes; and thus the dry land, formed by the debris of living creatures, is more and more disclosed. As the land emerges from the sea, the water from the clouds forms currents upon its surface, by which it is rent and excavated, and divided into valleys and mountains. With the exception of volcanoes, our steepest and most elevated ridges have formerly belonged to plains, even their substance once made a part of the bodies of animals and plants; and it is in consequence of being so long purified from foreign principles that they are reduced to a siliceous nature. But running waters furrow them in all directions, and carry their materials into the bed of the sea; and the latter, from continual efforts to deepen its bottom, necessarily throws them out on one side or other. Hence there results a general movement and a constant transportation of the ocean, which has perhaps already made several circuits of the globe. This shifting cannot occur without displacing the centre of gravity in the globe; a circumstance which would have the effect of displacing the axis itself, and changing the temperature of the different climates.—In order to silence any doubts that may arise in the minds of his readers from not observing these changes going forward, Lamarck is careful to add, as in the case of the supposed transformation of species, that an unlimited length of time must be allowed for their accomplishment.

But the work on which Lamarck’s fame is principally founded, and which has conferred a most important service on zoology, is his Histoire Naturelle des Animaux sans Vertébres. From the time of its appearance, this work has ever been regarded as one of the highest authority, and has formed the principal regulator of most departments of this extensive race of animals. The work extends to seven octavo volumes, and is entitled “Natural History of invertebrate Animals, presenting the general and particular Characters of these Animals, their Distribution, Classes, Families, Genera, and the principal Species referable thereto.” The first volume is entirely occupied with an introduction, the object of which is to determine the essential characters of an animal, its distinction from vegetables and other natural bodies, and to explain the fundamental principles of zoology. This introduction may be regarded as furnishing a synoptical view of all the author’s peculiar opinions on the origin and developement of living beings, which are illustrated more in detail in separate works. The first five volumes are written entirely by Lamarck, but he was assisted in the part relating to insects by M. Latreille. A portion of the sixth volume and the whole of the seventh, were drawn up by his daughter from his notes and papers, his want of sight preventing him from undertaking that labour himself; and that part of the sixth, which relates to the mytilacés, malliacés, pectinides, and ostracés, is written by M. Valenciennes. The first part was published in 1815, and the other parts appeared at intervals up to 1822, when the whole was completed. Besides a luminous and comprehensive account of the general history of the different groups and genera, the principal species are cited and briefly characterized, with their synonymes, reference to figures, and localities. The enumeration of species sometimes includes all the known kinds, and is particularly copious and instructive in relation to sponges and shell-bearing molluscæ. The genera are established with much discrimination, and judiciously characterized by obvious properties, such as form, proportion, nature of the surface, and structure. The synonymy is unravelled with great care, and the descriptions, though necessarily often very brief, are in general highly satisfactory. These circumstances have rendered this work the most valuable system that has ever appeared of the invertebrate animals; and it has formed the guide to most authors who have since written on the subject[18].

The phrase invertebrate animals originated with Lamarck, and it expresses, as Cuvier remarks, perhaps the only circumstances in their organization which is common to them all. They were previously known as white-blooded animals, a designation which was soon shown to be improper, by the discovery that an entire class (the annelides) possesses red blood. The system of Linnæus and Bruguière formed the basis of his course when he first began to lecture on the subject; he subsequently adopted a new classification, founded on their anatomy, which had been published in 1795. This he afterwards modified in various ways, as new discoveries were made, and as new relations suggested themselves to him. In his system of invertebrata, forming an octavo volume, published in 1810, he adopted the class of crustacea, and created that of arachnides, a step which he judged necessary, in consequence of some new information that had been communicated to him on the heart and pulmonary sacs of spiders. In a previous work he had admitted the annelides to the rank of a separate class, in consequence of Baron Cuvier’s observations on their circulating organs and the colour of their blood, which resembles that of the vertebrate races. Two other classes were created, in his “Philosophical Zoology,” viz. the infusoria and the centipedes; and in this work also he first deviated from the ordinary practice of commencing the arrangement with the most perfectly organized, the inverse order being more in accordance with his theoretical views, which assumed a gradual progression in the composition of animal organs, proceeding from the most simple to the most complex.

It was in a small volume, entitled “An Extract from the Zoological Course in the Museum of Natural History, on the invertebrate Animals,” &c. published in 1812, that he first presented his general distribution of animals into three grand divisions, apathetic, sentient, and intelligent. This plan he made the foundation of his great work, and the method in which he applied it, as well as his ideas regarding the constitution of the different classes, and their relation to each other, will be understood from the subjoined table.

Invertebrate Animals.I. Apathetic Animals.
1. Infusoria.
2. Polypes.
3. Radiarii.
4. Vermes. (Epizoaires.)
II. Sentient Animals.
5. Insecta.
6. Arachnides.
7. Crustacea.
8. Annelides.
9. Cirrhipedes.
10. Mollusca.
Vertebrate Animals.
III. Intelligent Animals.
11. Pisces.
12. Reptilia.
13. Aves.
14. Mammiferæ.

The animals of the first primary division he defines as destitute of feeling, and moving only by their excited irritability; and he assigns as their character, the absence of a brain and of an elongate medullary mass; senses wanting; forms various; articulations rarely existing. The animals of the second division feel, but they obtain from their sensations only perceptions of objects, a kind of simple ideas which they are unable to combine with each other in order to form complex ones. They possess no vertebral column, but have a brain and most frequently an elongate medullary mass; some distinct senses; organs of motion attached under the skin; the form symmetrical, the parts arranged in pairs. The intelligent animals, forming the third grand division, feel, and acquire ideas capable of being preserved, and execute operations between these ideas which furnish them with others; and they are intelligent in different degrees. They possess a vertebral column, a brain and spinal marrow; distinct senses; organs of motion fixed to an interior skeleton, and symmetrical forms, the parts being placed in pairs[19].