We have no sympathy with those who rail at all abstract ideas, as if they were imaginary essences or mere illusions; we recognize the faculty of abstraction as one of the wisest provisions of Nature, and one of the most useful powers belonging to the mind of man,--a power which comes into action with the first dawn of infant intelligence, and is only matured as reason rises into manhood, till it becomes the internal spring of all Philosophy and Science.

Nor do we hold that an abstract idea is necessarily an unreality, or a mere negation; for, without reviving the controversy between the Nominalists and Realists, or pronouncing any decision on the intricate questions which that controversy involved, we may say, in general terms, that the idea of a circle, of a square, or of a triangle, is neither unreal nor negative, but a very positive, and, withal, intelligible thing.

It is the idea of that which is essential to the nature of each of these figures respectively, and common to all possible figures of the same class, whatever may be their accidental varieties, whether in point of dimension or form.

And so the idea of Being or Substance, although it be highly abstract, is not necessarily unreal or negative; it is the idea of _existence_, or of that which is common to everything that _is_, abstraction being made of every diversity by which one being is distinguished from another.

Conscious that we ourselves exist, and observing that other beings exist around us, we strike off the peculiarities which belong to individuals, and form the general idea which includes nothing but what is common to all, and yet contains a positive element, which is the object of one of the strongest convictions of the human mind.[125] The conception of Infinite Being contains the positive element of _being_, abstraction being made of all _limitation_ or _bounds_.