In this single expression a whole train of facts are taken into the account, tho not particularly marked.  As a single expression we imply that trees increase their stature.  But this we all know could never be effected without the influence of other causes.  The soil where it stands must contain properties suited to the growth of the tree.  A due portion of moisture and heat are also requisite.  These facts all exist, and are indispensable to make good the expression that the “tree grows.”  We might also trace the capabilities of the tree itself, its roots, bark, veins or pores, fibres or grains, its succulent and absorbent powers.  But, as in the case of the “man that killed the deer,” noticed in a former lecture, the mind here conceives a single idea of a complete whole, which is signified by the single expression, “trees grow.”

Let the following example serve in further illustration of this point.  Take two bricks, the one heated to a high temperature, the other cold.  Put them together, and in a short time you will find them of equal temperature.  One has grown warm, the other cool.  One has imparted heat and received cold, the other has received heat and imparted cold.  Yet all this would remain forever unknown, but for the effects which must appear obvious to all.  From these effects the causes are to be learned.

It must, I think, appear plain to all who are willing to see, that action, as such, can never exist distinct from the thing that acts; that all our notions of action are derived from an observance of things in an acting condition; and hence that no words can be framed to express our ideas of action on any other principle.

I hope you will bear these principles in mind.  They are vastly important in the construction of language, as will appear when we come to speak of the agents and objects of action.  We still adhere to the fact, that no rules of language can be successfully employed, which deviate from the permanent laws which operate in the regulation of matter and mind; a fact which can not be too deeply impressed on your minds.

In the consideration of actions as expressed by verbs, we must observe that power, cause, means, agency, and effects, are indispensable to their existence.  Such principles exist in fact, and must be observed in obtaining a complete knowledge of language; for words, we have already seen, are the expression of ideas, and ideas are the impression of things.

In our attempts at improvement, we should strip away the covering, and come at the reality.  Words should be measurably forgotten, while we search diligently for the things expressed by them. Signs should always conduct to the things signified.  The weary traveller, hungry and faint, would hardly satisfy himself with an examination of the sign before the inn, marking its form, the picture upon it, the nice shades of coloring in the painting.  He would go in, and search for the thing signified.