Now truth is attributed both to knowledge and to things. We say that a person thinks or judges _truly_, that his knowledge is _true_ (or correct, or accurate), when things really are as he thinks or judges them to be. The truth which we thus ascribe to knowledge, to the mind interpreting reality, is _logical_ truth: a relation of concord or conformity of the mind interpreting reality—or, of the mind’s judgment about reality—with the reality itself.(162) Logical truth is dealt with in Logic and Epistemology. We are concerned here only with the truth that is attributed to reality, to things themselves: ontological, metaphysical, transcendental truth, as it is called. There is nothing abstruse or far-fetched about the use of the terms “true” and “truth” as equivalent to “real” and “reality”. We speak of “true” gold, a “true” friend, a “veritable” hero, etc. Now what do we mean by thus ascribing truth to a thing? We mean that it corresponds to a mental type or ideal. We call a liquid true wine or real wine, for instance, when it verifies in itself the definition we have formed of the nature of wine. Hence whenever we apply the terms “true” or “truth” to a thing we shall find that we are considering that thing not absolutely and in itself but in reference to an idea in our minds: we do not say of a thing simply that it is true, we say that it is _truly such or such_ a thing, _i.e._ that it is really of a certain nature already conceived by our minds. If the appearance of the thing suggests comparison with some such ideal type or nature, and if the thing is seen on examination not really to verify this nature in itself, we say that it is not really or truly such or such a thing: _e.g._ that a certain liquid is not really wine, or is not true wine. When we have no such ideal type to which to refer a thing, when we do not know its nature, cannot classify and name it, we have to suspend our judgment and say that we do not know what the thing _really_ is. Hence, for example, the new rays discovered by Röntgen were called provisionally “X rays,” their real nature being at first unknown. We see, then, that real or ontological truth is simply reality considered as conformable with an ideal type, with an idea in the mind.