But I am well aware that there are many Idealists who would repel it as an utterly unfounded charge that they fail to distinguish between a sensation or idea and what I will call its object. And there are, I admit, many who not only imply, as we all do, that green is distinct from the sensation of green, but expressly insist upon the distinction as an important part of their system. They would perhaps only assert that the two form an inseparable unity. But I wish to point out that many, who use this phrase, and who do admit the distinction, are not thereby absolved from the charge that they deny it. For there is a certain doctrine, very prevalent among philosophers nowadays, which by a very simple reduction may be seen to assert that two distinct things both are and are not distinct. A distinction is asserted; but it is _also_ asserted that the things distinguished form an 'organic unity,' But, forming such a unity, it is held, each would not be what it is _apart from its relation to the other._ Hence to consider either by itself is to make an _illegitimate abstraction._ The recognition that there are 'organic unities' and 'illegitimate abstractions' in this sense is regarded as one of the chief conquests of modern philosophy. But what is the sense attached to these terms? An abstraction is illegitimate, when and only when we attempt to assert of _a part_--of something abstracted--that which is true only of the _whole_ to which it belongs: and it may perhaps be useful to point out that this should not be done. But the application actually made of this principle, and what perhaps would be expressly acknowledged as its meaning, is something much the reverse of useful. The principle is used to assert that certain abstractions are _in all cases_ illegitimate; that whenever you try to assert _anything whatever_ of that which is _part_ of an organic whole, what you assert can only be true of the whole. And this principle, so far from being a useful truth, is necessarily false. For if the whole can, nay _must,_ be substituted for the part in all propositions and for all purposes, this can only be because the whole is absolutely identical with the part. When, therefore, we are told that green and the sensation of green are certainly distinct but yet are not separable, or that it is an illegitimate abstraction to consider the one apart from the other, what these provisos are used to assert is, that though the two things are distinct yet you not only can but must treat them as if they were not. Many philosophers, therefore, when they admit a distinction, yet (following the lead of Hegel) boldly assert their right, in a slightly more obscure form of words, _also_ to deny it. The principle of organic unities, like that of combined analysis and synthesis, is mainly used to defend the practice of holding _both_ of two contradictory propositions, wherever this may seem convenient. In this, as in other matters, Hegel's main