Principles of Human Knowledge
George Berkeley, the metaphysician, was born on March 12, 1685, near Thomastown, Kilkenny, the son of a collector of revenue. He entered Trinity College, Dublin, at the age of fifteen, and was admitted Fellow in 1707. In that year he published two mathematical essays; two years later, his "Theory of Vision," and in 1710 his "Principles of Human Knowledge." In 1713, in London, where he had published further philosophical papers, he formed the acquaintance of Steele, Swift, and Pope. After travels in Europe he became chaplain to the Lord-Lieutenant of Ireland in 1721, and a few years after emigrated to Newport, Rhode Island, with a view to the establishment of a college in Bermuda for the education of Indians. This scheme fell through, because of the failure of the promised government support. Berkeley returned to London, and in 1734, by desire of Queen Caroline, was consecrated Bishop of Cloyne, in Ireland. Here he lived until 1752, but spent his last months in retirement at Oxford, where he died on January 14, 1753. Berkeley's "Principles of Human Knowledge" is one of the most eminent of that sequence of metaphysical systems which, beginning with Descartes, constitutes what is known as modern philosophy.
I.--The Analysis of Perception
It is evident to anyone who takes a survey of the objects of human knowledge that they are either ideas actually imprinted on the senses, or else such as are perceived by attending to the passions and operations of the mind; or, lastly, ideas formed by help of memory and imagination, either compounding, dividing, or representing those originally perceived in the aforesaid ways. By sight, touch, and other senses, I receive various sensations; and any group of sensations, frequently accompanying one another, come to be known as one thing. Thus a certain colour, taste, smell, figure, and consistence, having been observed to go together, are accountedone distinct thing--for instance, an apple.
But, besides this endless variety of objects of knowledge, there is also the "mind," "spirit," "soul," or "myself," which perceives them. Neither our thoughts or imaginations, nor even the sensations which compose the objects of perception, can exist otherwise than in a mind perceiving them. It is impossible that objects should have any existence out of the minds for which they exist; to conceive them as existing unperceived is a mere abstraction. Whence it follows that there is no other substance but spirit, or that which perceives.
Some, indeed, distinguish between "primary" and "secondary" qualities, and hold that the former, such as extension, figure, motion, and solidity, have some existence outside of the mind in an unthinking substance which they call "matter." But extension, figure, and motion are only ideas existing in the mind, and neither these ideas nor their archetypes can exist in an unperceiving substance. The very notion of what is called "matter" involves a contradiction within it. Not only primary and secondary qualities alike, but also "great" and "small," "swift" and "slow," "extension," "number," and even "unity" itself, being all of them purely relative, exist only in the mind. The conception of "material substance" has no meaning but that of "being" in general.
Even if we were to give to the materialists their "external bodies," they are by their own confession no nearer to knowledge how our ideas are produced, since they own themselves unable to comprehend in what manner body can act upon spirit, or how it is possible that it should imprint any idea on the mind.
It is evident that the production of ideas in our minds can be no reason why we should suppose corporeal substances to exist, since the rise of those ideas is acknowledged to remain equally inexplicable with or without the supposition of material existences. In short, if therewere external bodies, it is impossible that we should ever come to know it; and if there were not, we should have the same reasons to think there were, that we have now. We perceive a continual succession of ideas; some are anew excited, others are changed or totally disappear. There is, therefore, some cause of these ideas, whereon they depend, which produces and changes them. This cause must be a substance; but it has been shown that there is no corporeal or material substance. It remains, therefore, that the cause of ideas is an incorporeal active substance or spirit.
A spirit is one simple, undivided, active being; as it perceives ideas it is called the "understanding," and as it produces or otherwise operates about them, it is called the "will." Such is the nature of spirit that it cannot be of itself perceived, but only by the effects which it produceth.
The ideas of sense are more strong, lively, and distinct than those of the imagination; they have likewise a steadiness, order, and coherence, and are excited in a regular series, the admirable connection whereof sufficiently testifies the wisdom and benevolence of its Author. The set rules or established methods, wherein the mind that we depend on excites in us the ideas of sense, are called the "laws of Nature."