es in accordance with which we must think in order to inform our practice. It is not, therefore, an a priori inquiry of the sort Kant imagined, but it starts, as Marx and Engels said, from "real premises" which are "verified in a purely empirical way".
At the same time, it is by no means the same as stating the laws in accordance with which subjective processes of thought proceed, as contrasted with the laws (studied by empirical sciences) in accordance with which objective processes proceed. Indeed, such a misunderstanding is an absurd onefor thought‑processes are just as "objective" as any other processes, and to find out how they proceed requires, as for any other processes, examining the evidences of their occurrence. The generalised principles of materialism and dialectics no more provide information, additional to that obtainable by empirical means, about thought‑processes and how they proceed than they do about any other processes and how they proceed. And they apply equally to both. They are not statements of information but principles of its assembly. But as such they do serve to correct erroneous views (those that take the form of illusion and fantasy), and consequently to specify the category‑formation of truthful views.
It is in this sense (and a very important sense it is) that the working out of the principles of materialism and dialectics may be said, in Ryle's words, to inform us about the "nature of things", and of their reflection in human thought; or, as Engels put it (Ludwig Feuerbach, 4), materialist dialectics becomes "the science of the general laws of motion both of the external world and of human thought". How things are and move (the forms of interconnection, the transformations of quantity into quality, the contradictions), and how this movement is to be reflected in our thought, is the discovery of materialist dialectics.
Principles of materialist dialectics, then, are expressible in less negative and "frivolous" terms than Ryle supposed, when he observed that the conclusion that "the Cheshire Cat could not leave its grin behind it" enlightened us "about the nature of things". For what we learn from these principles is of considerably greater and more general practical importance. Thus, for example, the conclusion that "it is not the consciousness of men that determines their being, but their social being that determines their consciousness", or, more generally, that "being is prior to thinking", is at once more generalised than a principle about cats and their grins, and what we learn from it is in practice more important for ussince in practice no one gets led astray by supposing that grins exist independently of faces, whereas many get led astray by supposing that thinking or consciousness exists independently of real individuals and their social being. Similarly with conclusions about the dependence of qualitative changes on quantitative ones, and other "laws of dialectics".
If we consider principles of materialist dialectics, such as those mentioned as having been first formulated by Marx and Engels, my contention in this chapter is that they evidently differ from the generalisations arrived at by the empirical sciences in that they are not established and tested by the same type of directed observation and empirical test, and that their applicability in the guidance of practice is therefore also not of the same sort. Their character and application is essentially that of "laws of thought", as Engels already emphasised when he included "dialectics" along with "formal logic" in "the science of thought and its laws", stressing that it was demonstrable "independently" of "the positive science of nature and history".
However, this does not entail, as Kant supposed in his fanciful theory of "synthetic a priori knowledge", that they are somehow spun out of the inner resources of the mind and imposed by the mind upon "the phenomenal world" which it constructs for itself as its "object". On the contrary, they are indubitably and universally true of the processes of the real world, which we get to