he will lose the idea of those things which were signs of his being rational, whilst, nevertheless, the idea of a body-animated remains still before his eyes, so that the idea of rational is substracted from the whole idea of man, that is to say, of body-animated-rational, and there remains that of body-animated; and a while after, at a greater distance, the idea of animated will be lost, and that of body only will remain; so that at last, when nothing at all can be seen, the whole idea will vanish out of sight. By which examples, I think, it is manifest enough what is the internal ratiocination of the mind without words. We must not therefore think that computation, that is, ratiocination, has place only in numbers, as if man were distinguished from other living creatures (which is said to have been the opinion of _Pythagoras_) by nothing but the faculty of numbering; for _magnitude, body, motion, time, degrees of quality, action, conception, proportion, speech and names_ (in which all the kinds of philosophy consist) are capable of addition and substraction. Now such things as we add or substract, that is, which we put into an account, we are said to _consider_, in Greek λογίζεσθαι, in which language also συλλογίζεσθαι signifies to _compute_, _reason_, or _reckon_. [Sidenote: Properties, what they are.] 4. But _effects_ and the _appearances_ of things to sense, are faculties or powers of bodies, which make us distinguish them from one another; that is to say, conceive one body to be equal or unequal, like or unlike to another body; as in the example above, when by coming near enough to any body, we perceive the motion and going of the same, we distinguish it thereby from a tree, a column, and other fixed bodies; and so that motion or going is the _property_ thereof, as being proper to living creatures, and a faculty by which they make us distinguish them from other bodies. [Sidenote: How Properties are known by Generation, and contrarily.]