The relativity of form and matter, or of form and content, is indeed almost a commonplace of popular discussion on logical subjects. But like other uncritical applications of great truths, this is both carried beyond its proper bounds, and is not carried out with sufficient thoroughness. There cannot--it is said--be a formal logic, because every exercise of thought is internally affected or modified by the material--the subject-matter--with which it deals. It is implied in such an argument that the 'subject-matter' finds no difficulty in existing by itself, but that the 'thought' is a mere vacuity or un-characterised something which owes its every character to the said matter. But a subject-matter which has content and character has therefore form: it is already known, already thought. And as to this thought, which is said to approach its matter with a self so blank, so impartial, so neutral--what is it? It is a thought or a thinking which has never as yet thought,--which is only named 'thought' by right of expectation, but is itself nothing actual. Of such --fictitious--thought there can hardly be a science.
On the other hand, that may be easily called a formal logic, which is much more than formal: and that may be called material, which is only a species of formal. Great indeed is the virtue of names, to suppress and to replace thought. When forms hang on as mysterious names after their day is passed--when they are retained in a certain honour, while the real working methods have assumed other titles; then these forms become purely formal and antiquated. Thus the Logic of Aristotle seemed in its unfamiliar language to a later generation to be purely formal and superfluous. It was only another side of the same mistake when the new forms--the forms efficient and active in matter,--were not recognised as formal, but were boldly styled material: and the Logic which discussed such matter-marked forms was called a material Logic.
The phrase Matter of Thought, like its many congeners, is a fruitful mother of misconceptions. Caught up by the pictorial imagination, which is always at hand to anticipate thought, it suggests a matter, which is not thought, but is _there,_ all the same, lying in expectation of it. It suggests two things--(for are there not two words, and a preposition or term of relation between them?). But there are not two things. This _matter_ is just as much a nonentity as the aforesaid _thought_: a matter of thought is a thought matter,--matter, thought once, and possibly to be thought again.