If anyone who reads these pages is not clear about the issue stated in the preceding paragraphs, a few examples should suffice to dispel the belief that any common thread of meaning runs through the subject-object distinction. That nothing of the sort exists is sufficiently evident if we consider verb-couplets which have a reciprocal relation, e.g. stimulate and respond. Thus X (subject) reacts to Y, means the same as Y (subject) stimulates X. In fact the logical, as distinct from the grammatical, status of the subject depends on the progress of knowledge. If the eye emits light, as Plato taught, the logical relations of subject and object are the same in the two following statements : (a) I see the flash, (b) I strike the table. In both of them the speaker-subject is the Platonic agent, and the so-called object is the goal or victim of the process. The fact that photography is possible shows that Plato was wrong. So it is clear that the flash (grammatical object) is the agent (logical subject) of the first statement. This is not an isolated case. Whether we identify the grammatical subject of affective verbs such as love or wish with the agent of the process described by these words depends on whether we cling to traditional idealistic views about cognition and sentiment or whether we prefer to anticipate a more strictly behaviourist attitude. If we define the logical subject as the agent of a process, a solipsist view of the world prescribes that the logical is also the grammatical subject of: I remember, I remember the house where I was born. The behaviourist view, which is also that of the practical man or woman, prescribes that the house is the agent which initiates the type of cerebral activity called memory.
What we choose to call subject and object from a grammatical point of view thus depends on the grammatical apparatus of the language under discussion. In our own, we can use they and them as litmus paper. That is to say, the category of words which they can replace defines the subject class. In the sentence they respond to them, they can refer only to the things or persons stimulated, never to the stimulus. We have thus a class of verbs in which the grammatical subject of a process or action is what gets the stimulus. We also have a class of verbs (e.g. excite, stimulate) of which the grammatical subject is the stimulus itself, a class of verbs of which the