It is an axiom in mental philosophy, that we can think of nothing
which we have not perceived. When I say that we can think of nothing,
I mean, we can imagine nothing, we can reason of nothing, we can
remember nothing, we can foresee nothing. The most astonishing
combinations of poetry, the subtlest deductions of logic and
mathematics, are no other than combinations which the intellect
makes of sensations according to its own laws. A catalogue of all
the thoughts of the mind, and of all their possible modifications,
is a cyclopedic history of the universe.
But, it will be objected, the inhabitants of the various planets of
this and other solar systems; and the existence of a Power bearing
the same relation to all that we perceive and are, as what we
call a cause does to what we call effect, were never subjects of
sensation, and yet the laws of mind almost universally suggest,
according to the various disposition of each, a conjecture,
a persuasion, or a conviction of their existence. The reply is
simple; these thoughts are also to be included in the catalogue
of existence; they are modes in which thoughts are combined; the
objection only adds force to the conclusion, that beyond the limits
of perception and thought nothing can exist.
Thoughts, or ideas, or notions, call them what you will, differ
from each other, not in kind, but in force. It has commonly been
supposed that those distinct thoughts which affect a number of
persons, at regular intervals, during the passage of a multitude
of other thoughts, which are called REAL or EXTERNAL OBJECTS,
are totally different in kind from those which affect only a few
persons, and which recur at irregular intervals, and are usually
more obscure and indistinct, such as hallucinations, dreams, and the
ideas of madness. No essential distinction between any one of these
ideas, or any class of them, is founded on a correct observation of
the nature of things, but merely on a consideration of what thoughts
are most invariably subservient to the security and happiness of
life; and if nothing more were expressed by the distinction, the
philosopher might safely accommodate his language to that of the
vulgar. But they pretend to assert an essential difference, which
has no foundation in truth, and which suggests a narrow and false
conception of universal nature, the parent of the most fatal errors
in speculation. A specific difference between every thought of the
mind, is, indeed, a necessary consequence of that law by which it
perceives diversity and number; but a generic and essential difference
is wholly arbitrary. The principle of the agreement and similarity
of all thoughts, is, that they are all thoughts; the principle
of their disagreement consists in the variety and irregularity of
the occasions on which they arise in the mind. That in which they
agree, to that in which they differ, is as everything to nothing.
Important distinctions, of various degrees of force, indeed, are to
be established between them, if they were, as they may be, subjects
of ethical and economical discussion; but that is a question
altogether distinct. By considering all knowledge as bounded by
perception, whose operations may be indefinitely combined, we arrive
at a conception of Nature inexpressibly more magnificent, simple
and true, than accords with the ordinary systems of complicated and
partial consideration. Nor does a contemplation of the universe,
in this comprehensive and synthetical view, exclude the subtlest
analysis of its modifications and parts.
A scale might be formed, graduated according to the degrees
of a combined ratio of intensity, duration, connexion, periods of
recurrence, and utility, which would be the standard, according to
which all ideas might be measured, and an uninterrupted chain of
nicely shadowed distinctions would be observed, from the faintest
impression on the senses, to the most distinct combination of those
impressions; from the simplest of those combinations, to that mass
of knowledge which, including our own nature, constitutes what we
call the universe.
We are intuitively conscious of our own existence, and of that
connexion in the train of our successive ideas, which we term our
identity. We are conscious also of the existence of other minds;
but not intuitively. Our evidence, with respect to the existence of
other minds, is founded upon a very complicated relation of ideas,
which it is foreign to the purpose of this treatise to anatomize.
The basis of this relation is, undoubtedly, a periodical recurrence
of masses of ideas, which our voluntary determinations have, in
one peculiar direction, no power to circumscribe or to arrest, and
against the recurrence of which they can only imperfectly provide.
The irresistible laws of thought constrain us to believe that the
precise limits of our actual ideas are not the actual limits of
possible ideas; the law, according to which these deductions are
drawn, is called analogy; and this is the foundation of all our
inferences, from one idea to another, inasmuch as they resemble
each other.
We see trees, houses, fields, living beings in our own shape, and
in shapes more or less analogous to our own. These are perpetually
changing the mode of their existence relatively to us. To express
the varieties of these modes, we say, WE MOVE, THEY MOVE; and as this
motion is continual, though not uniform, we express our conception
of the diversities of its course by--IT HAS BEEN, IT IS, IT SHALL
BE. These diversities are events or objects, and are essential,
considered relatively to human identity, for the existence of the
human mind. For if the inequalities, produced by what has been
termed the operations of the external universe, were levelled by the
perception of our being, uniting and filling up their interstices,
motion and mensuration, and time, and space; the elements of the
human mind being thus abstracted, sensation and imagination cease.
Mind cannot be considered pure.
II--WHAT METAPHYSICS ARE. ERRORS IN THE USUAL METHODS OF CONSIDERING
THEM
We do not attend sufficiently to what passes within ourselves. We
combine words, combined a thousand times before. In our minds we
assume entire opinions; and in the expression of those opinions,
entire phrases, when we would philosophize. Our whole style of
expression and sentiment is infected with the tritest plagiarisms.
Our words are dead, our thoughts are cold and borrowed.
Let us contemplate facts; let us, in the great study of ourselves,
resolutely compel the mind to a rigid consideration of itself. We
are not content with conjecture, and inductions, and syllogisms,
in sciences regarding external objects. As in these, let us also,
in considering the phenomena of mind, severely collect those
facts which cannot be disputed. Metaphysics will thus possess this
conspicuous advantage over every other science, that each student,
by attentively referring to his own mind, may ascertain the
authorities upon which any assertions regarding it are supported.
There can thus be no deception, we ourselves being the depositaries
of the evidence of the subject which we consider.
Metaphysics may be defined as an inquiry concerning those things
belonging to, or connected with, the internal nature of man.
It is said that mind produces motion; and it might as well have
been said, that motion produces mind.