The presumption to which biological science brings one is that the senses and mind will work as well as the survival of the species may require, but that they will not work so very much better. There is no ground in matter-of-fact experience for assuming that there is any more inevitable certitude about purely intellectual operations than there is about sensory perceptions. The mind of a man may be primarily only a food-seeking, danger-avoiding, mate-finding instrument, just as the mind of a dog is, just as the nose of a dog is, or the snout of a pig.
You see the strong preparatory reason there is in this view of life for entertaining the suppositions that:—
The senses seem surer than they are.
The thinking mind seems clearer than it is and is more positive than it ought to be.
The world of fact is not what it appears to be.
1.5. THE CLASSIFICATORY ASSUMPTION.
After I had studied science and particularly biological science for some years, I became a teacher in a school for boys. I found it necessary to supplement my untutored conception of teaching method by a more systematic knowledge of its principles and methods, and I took the courses for the diplomas of Licentiate and Fellow of the London College of Preceptors which happened to be convenient for me. These courses included some of the more elementary aspects of psychology and logic and set me thinking and reading further. From the first, Logic as it was presented to me impressed me as a system of ideas and methods remote and secluded from the world of fact in which I lived and with which I had to deal. As it came to me in the ordinary textbooks, it presented itself as the science of inference using the syllogism as its principal instrument. Now I was first struck by the fact that while my teachers in Logic seemed to be assuring me I always thought in this form:—
“M is P,
S is M,
S is P,”
the method of my reasoning was almost always in this form:—