process of abstraction, but the principles of Science155 and natural philosophy must be gained by experiment; and the latter young men talk of but do not realise, while the nature of the former is plain and clear.
Again, in matter of practice, error attaches either to the general rule, in the process of deliberation, or to the particular fact: for instance, this would be a general rule, “All water of a certain gravity is bad;” the particular fact, “this water is of that gravity.”
And that Practical Wisdom is not Knowledge is plain, for it has to do with the ultimate issue,156 as has been said, because every object of action is of this nature.
To Intuition it is opposed, for this takes in those principles which cannot be proved by reasoning, while Practical Wisdom is concerned with the ultimate particular fact which cannot be realised by Knowledge but by Sense; I do not mean one of the five senses, but the same by which we take in the mathematical fact, that no rectilineal figure can be contained by less than three lines, i.e. that a triangle is the ultimate figure, because here also is a stopping point.