LECTURE X.

In the present discourse I am to show that theorists are solicitous about names and definitions, because their speculations are often verbal deductions from such names: for instance, if they wish to prove that the surface of a pond is not level, they must premise that the earth is a sphere, and the pond a part of its circumference.

The error of this process is, that words have as many significations as they have applications to different phenomena; consequently, though the assertion is true when applied to an artificial sphere, that no part of its circumference is level; yet the assertion is sophistical when the word sphere is applied to the earth, because sphere has then a different signification.

So curiously have some theories become confounded verbally with sensible phenomena, that when I lately

asked a friend what he meant by saying the earth was round, he thought I was trifling with him. When I pressed him for an answer, he said it was round like any other round body. I desired an example. He pointed to an artificial globe. But, said I, in what is the earth like the globe? Does it present the same sight, or the same feel? Neither :-but when a fly walks over the globe, he produces an appearance similar to what a receding ship exhibits to spectators on the shore. Again, when a ship sails in a continued course westwardly, it returns to the country whence it originally departed; as a fly returns when he walks on an artificial globe. Besides, the shadow of an artificial globe resembles the appearance which is exhibited on the moon when eclipsed; an appearance which we are assured by astronomers is the shadow of the earth.

True, said I, the earth exhibits these phenomena, and hence you deduce its sphericity. All that I wish is to convince you that the word sphere, when applied to the earth, is not the name of a sight and feel, (as it is when applied to an artificial globe) but the name of certain other phenomena. It would be idle to prove by argument that an artificial globe is spherical. We can see and feel it, and thus decide immediately. But we cannot act thus with the earth; hence it has been repeatedly subjected to experiments, for the procurement of data from which its shape might be inferred. If, then, we would avoid the latent sophistry of language, we must carefully remember that the word sphere, when applied to the earth, is a name of these data only.

If I admit that there is fire in my hand, you may deduce The conclusion therefrom that my hand will be burnt.

seems inevitable. But you ought to know first whether I apply the word fire to what you have always found productive of such a result. Perhaps I hold in my hand paper on which the word fire is written. This, however, you would denounce as a quibble. It is a quibble, and a vast many philosophical conclusions are produced by a process similar in character to the quibble, though not so obvious to detection.

If we employ language simply to refer to phenomena, no serious evil can arise from the terms we adopt ; but if we select words to draw from them logical deductions, the slightest change of phraseology may produce in philosophy revolutions which no man can foresee till he has found all the consequences that may be logically deduced from the new names which he introduces. The metaphysician who concludes his book by asserting that nothing exists exterior of his mind, might have concluded it by asserting that every thing is exterior, if he had only named the objects of his knowledge impressions instead of ideas.

Dougald Stewart, in his Essays, says, "the assertion of Berkeley, that extension and figure have merely an ideal existence, tends to unhinge the whole frame of the human understanding, by shaking our confidence in those principles of belief which form an essential part of its constitution."

What serious consequences from the use of a new phrase! But, if we consider the language of Berkeley as merely a designation of phenomena, his phraseology will be unimportant. We may call extension and figure either ideal existences, or material existences, and our language will mean- -What? Just what you see and Our knowledge of phenomena must be identical,

feel.

though our language in relation to them may be diverse. If, however, we use language for the purpose of deducing consequences from names, the phraseology is important; but the importance is founded in ignorance of the nature of language.

Again: Mr. Stewart says, " In consequence of the writings of Reid and a few others, the word idea itself is universally regarded as a suspicious and dangerous term ; and it has already lost its technical or cartesian meaning, by being identified as a synonime with the more popular word notion."

Here philosophy is improved by simply substituting the word notion for the word idea. But why? Because the verbal consequences which we deduce from the word idea cannot be deduced from the word notion. The change of phraseology is an improvement, because we make an improper use of language. We know not that the meaning of a word fluctuates with the phenomenon to which it refers.

In the system of one philosopher, "ideology is stated to be a branch of zoology, and to have for its object an examination of the intellectual faculties of man and of other animals." Mr. Stewart is startled at this phraseology, and says "the classification is extraordinary, and it is obviously intended to prepare the way for an assumption which levels men with the brutes."

If phi

A very serious effect from a cause so trivial ! losophers can, with a dash of their pen, level men with brutes, we may account as authentic history the enchantments of Circe. But the most which any writer can accomplish is to transform names. Philosophers may apply to brutes, as well as men, the phrase intellectual faculties;

but the phenomena exhibited by both will not become identical from possessing the same name. Philosophers can extend to quadrupeds the term man, but even this will not level men with brutes; it will level the name only. The phenomena which give significance to the name, will continue distinct and inconvertible.

Whether the earth be named a sphere or a plane is of little consequence, so long as we use the name to designate the phenomena only which are exhibited by the earth; but the name becomes essential, if we employ it to deduce therefrom what our senses cannot discover. Whether two perpendicular poles that may stand before me are parallel, depends entirely on the name by which I designate the earth. If I use the word sphere, the two poles are not parallel, maugre all that seeing and feeling can testify to the contrary; because you can mathematically demonstrate that no two lines perpendicular to the surface of a sphere can be parallel.

The phenomena exhibited by the heavenly bodies are equally apparent to all men; and whether we call them the motion of the heavenly bodies around the earth, or the motion of the earth around its own axis, and around the sun, is unimportant, so long as we employ the words to name the phenomena only which our senses discover: but when we proceed beyond our senses, the phraseology is very important. By adopting the latter phraseology we make all mankind travel, at a giddy velocity, of more than a thousand miles a minute in one direction, and about a thousand miles an hour in another direction. If the phenomena be named the motion of the heavenly bodies, we escape from disturbing the quiescence of the earth; but we unmercifully cause the sun and stars to