Aristotle's On Interpretation Ch. 9. segment 19a8-19a22: A portion of the future finds its origin in our own deliberation and action. Therefore, the future cannot be predetermined

(19a8-19a22) of Ch. 9: A portion of the future finds its origin in our own deliberation and action. Therefore, the future cannot be predetermined

So far, Aristotle has spent the first part of Ch. 9 contending with the theory that our future unfolds according to a predetermined plan. According to this theory, something which is external to us is the author of our future and has already determined whether we will have breakfast tomorrow, at what time and place we will have it and of what it will consist. This theoretical position hinges on the idea that every assertion is already true or false when we utter it. For example, if someone asserted ten years ago that we will have breakfast tomorrow at 8 o’clock at a fancy restaurant, then whether we will indeed have breakfast at a fancy restaurant tomorrow morning depends on whether the assertion of that person was true or false then. Yet, as Aristotle observes in Ch. 9 18b26-19a7 it is not the truth or falsity of some assertion which determines what comes to be. It is rather what comes to be which indicates to us which assertion proves true and which false.

In the present text, Aristotle endeavours to disprove the idea that the future is predetermined altogether. To do this, he first acknowledges that some things consistently happen in a certain way and seemingly cannot happen in any other way. One example is that the Sun always rises in the East. Once we grasp that the conditions which bring this about, i.e. the movements of the Earth in relation to the Sun, are constant, we will be hard-pressed to consider the possibility that the Sun will one day not rise in the East. We will thus have no grounds to claim it possible that the assertion “the Sun will not rise in the East” is true or “the Sun will rise in the East” is false.

Be that as it may, Aristotle only mentions such cases in order to facilitate a discussion about the things which are not ruled by constants and have no fixed outcomes. More specifically, he wants to draw our attention to that portion of the future which lies in human hands. That is, he brings our focus to those future possibilities which find their origin in our own deliberation and actions. For example, we cannot dictate where or when the Sun rises each day. Yet, we may make plans to watch the sunrise tomorrow and then act on these plans. As such, whereas the constants that underlie each sunrise only make it possible for the Sun to rise in the East, we maintain both the possibility to watch the sunrise and to not watch it.

Now, if we wish to watch the sunrise tomorrow, we ought to come up with an appropriate course of action and carry it out. That is, we ought to deliberate on how we can make our wish come true, then act and make it true. By way of illustration, we will first need to figure out when the Sun will rise tomorrow and where we will best be able to watch it. We may next work out when we need to wake up so that we can make it there in time. We will then need to actually wake up at that time and head to our destination. Even in this way, in spite of our carrying out our plan to the letter, all sorts of chance obstacles may arise and keep our wish from coming true (e.g. an unexpected cloud covers the Sun as it rises). All the same, if we do wish to watch the sunrise tomorrow, we must orient our thoughts and actions in such a way that this becomes a possible outcome. Yet, even if we do not now wish to watch the sunrise tomorrow, there still remains a possibility that we will change our minds (e.g. a friend may talk us into it). As such, It remains both possible that will watch the sunrise tomorrow and that we will not watch it. This leaves us in a position where we cannot determine which of the two contradictory assertions “we will watch the sunrise tomorrow” and “we will not watch the sunrise tomorrow” is true and which false.

Therefore, given that we have demonstrated that some of what will be remains in our hands and that a measure of the future relies on chance, it follows that the future cannot be predetermined. In other words, the theory that the future has already been determined is false. 

Moreover, even when we consider things which consistently produce the same outcome (e.g. the Sun always appears to rise in the East), we cannot completely rule out the other possibility, however slim. Afterall, something might eventually happen which will alter the constants which keep such outcomes fixed.

Key points: (i) One theory suggests that the future unfolds according to a predetermined plan. (ii) Be that as it may, a portion of the future remains in our hands. That is, the future is filled with possibilities which find their origin in our own deliberation and actions. (iii) Therefore, the theory which suggests that every future occurrence has been predetermined is false.

“Above the Clouds at Sunrise” by Frederic Edwin Church ca. 1849