This book has three interrelated topics: rationality, time, and self. I will reveal their connection through a consideration of indexical language and the beliefs it expresses. In particular, their connection will be brought out through a consideration of the role of our beliefs in our everyday actions.

I take the nature of time to be a topic which is of great importance because our world is temporal. Everything we do and everything we know about is in time or at least, depending upon one’s opinion of abstract entities, a great many things we know about are in time. Because of time’s pervasive nature we can consider it through considering the nature of our lives as rational creatures who are active and emotional.

Tensed language appears to say something different about the world than tenseless language. We appear to know something different about an event when we know that it is future, than we do when we simply know tenselessly that it occurs at a specific time or after another event. We can know the two tenseless things but still not know if the event has happened yet. This difference appears to concern the nature of time. I believe that these appearances are correct. There is an objective distinction between something being future, it being present, or it being past which is captured by tensed language and in this respect tensed beliefs but which is not captured by tenseless language or beliefs. To accept this is to adopt a tensed theory of time and my primary aim in this book is to provide an argument to show that this theory is correct, A1.

Not everyone shares my opinion and I refer to those who disagree as tenseless theorists.¹ The tensed theory relies on two ideas. First, tensed language plays a different role in our lives than tenseless language. Second, this difference in roles involves a difference in what is described by the language. The former of these ideas allows us to distinguish tensed and tenseless beliefs as the different beliefs one portrays with the different language. The latter idea allows us to speak of these beliefs as involving an awareness of different states of the world, or facts.

It is possible to challenge both of these ideas and tenseless theorists have done so. Thus I have two secondary aims in this book. First, I will defend the idea that different roles are played by tensed and tenseless beliefs and language, A2. Second, I will defend the idea that this involves them capturing something different about the world, A3.

Early in the twentieth century the opinion was popular in philosophy that tensed and tenseless language did not play different roles and that they could in fact be inter-substituted for one another. This view went hand-in-hand with the popularity of standard first-order logic which symbolized the two equally. Since then, however, this view has gone out of popularity and today it is widely recognized that the two are not inter-substitutable, but rather differ in meaning. This is a view accommodated by the invention of tense logic.

There are two broad reasons for this change in opinion. Firstly, it has been recognized that tensed and tenseless aspects of language really do play different roles. There are occasions in which the former can be used and the latter cannot. This difference has been noted in a consideration of our everyday actions and emotions. Knowing that I have to cook supper tonight motivates me to go shopping in a way in which simply knowing anything tenseless does not. For example, knowing an obligation for me to cook falls on the 9th of December 2017 might leave me unmoved even though it is the 9th of December 2017 if I do not know that is now the date. Similarly, I might be anxious because I know I am going to cook tonight and not because of any tenseless knowledge I have, such that I am going to cook on the 9th of December 2017.

Secondly, advances have been made in the philosophy of language that provide powerful theories of meaning according to which tensed and tenseless elements of language mean different things. There has been a growth in the popularity of direct reference theories of indexical language according to which indexical language, including tensed language , has an element of meaning akin to the rules of use for that language. This element of meaning distinguishes tensed and tenseless language, because whilst one might use both ‘now’ and ‘11:15’ to pick out the same time ‘now’ can also be used to pick out other times in a way in which ‘11:15’ cannot.

To this extent A2 is generally accepted. No doubt these two motivations for accepting it are related because two sentences which cannot be used for the same linguistic purposes amongst speakers who understand both clearly differ in meaning.

In denying A3 tenseless theories of language and truth have been offered according to which a difference in meaning can go hand-in-hand with an identity of truth-makers. That is, it has been argued that whilst tensed and tenseless aspects of language differ in meaning the truth-makers of both can coincide. Moreover, we can express the truth-makers of a use of tensed language with tenseless language and hence we can suppose that the former does not capture facts which the latter does not because the truth-makers can coincide. For example, it is suggested that a use of ‘it is raining now’, said at 11:20 on the 9th of December 2017, will be true if and only if rain occurs [tenseless] at 11:20 on the 9th of December 2017. This latter fact can be captured with tenseless language and therefore tensed and tenseless uses of language can share truth-makers and be taken to capture the same facts.

This allows the tenseless theory to accept A2 and to explain the different roles that tensed and tenseless aspects of language have in terms of their differing in meaning. This can be done without needing to recognize that the two capture different facts because the difference in meaning does not entail a difference in truth-makers. A3 is denied.

However, a fuller consideration of the different roles tensed and tenseless beliefs play in actions and emotions reveals the importance of rationality (or perhaps appropriateness in the latter case). It is not the case that people cannot be motivated by tenseless beliefs in everyday actions. But, very often they would be acting irrationally if they were to be. I may be motivated to shop because I have the tenseless knowledge that I am obliged to cook on the 9th of December 2017. But, it would be irrational of me to be motivated in this way if I do not know what the current date is (and hence have a tensed belief too) . If it is now the 10th of December 2017 or the 10th of June 2017 shopping is pointless.

In a related way, my anxiety that I have to cook today is only appropriate if I have to cook today. Whereas, it is not clear it can be appropriate at all to have a tenseless anxiety because we ought only to be anxious about the future and a tenseless anxiety will be one which is seemingly indifferent to this. If it is the 10th of December 2017 today, then I oughtn’t to be anxious about having an obligation to cook on the 9th of December 2017.

Since the middle of the last century it has been commonly believed that actions are caused by belief/desire complexes which provide the reasons for those actions. I refer to this view as psychologism about reasons. Psychologism easily accommodates a tenseless acceptance of A2 and denial of A3 because it focuses on the nature of the beliefs themselves rather than what they are an awareness of in its account of an action and its rationality.

In more recent times, however, psychologism has come under increasing attack. There is now a trend of recognizing that reasons for action are facts and hence that the role of a belief in a rational action is determined by its object —the facts it is an awareness of. This non-psychologism does not sit well with an acceptance of A2 and a denial of A3. Rather, it implies that A2 follows from A3. It is because tensed and tenseless beliefs capture different facts that they can play different roles in rational action. This is an issue apparently unnoticed by tenseless theorists to date.

My method in this book will thus be to argue that rational action differentiates between tensed and tenseless beliefs. In this way I defend A2 in a way that goes beyond its already popular acceptance. I will defend a form of non-psychologism about reasons for action, and will use this to argue that the difference in the roles of tensed and tenseless beliefs stems from a difference in the facts they capture. In this way my defence of A3 will be in tune with contemporary achievements in the philosophies of rationality and action, and will thereby bring these into concert with the philosophy of time in a way which is currently lacking to the detriment to each of these fields. A2 and A3 lead to A1 given our actions are by and large rational. The tensed theory of time is thus established through a consideration of our nature as rational animals.

In the last fifty years it has become popular in the philosophy of emotions to think that emotions are not mere feelings and that they also involve cognitive aspects. They are related to beliefs. It is also increasingly popular to speak of the appropriateness of emotions. To the extent that this has come into contact with the philosophy of time it has again been argued that it coincides with a tenseless acceptance of A2 and denial of A3. A form of psychologism is adopted according to which the beliefs involved in emotions can affect their appropriateness independently of the objects of those beliefs.

However, these moves have been made without a consideration of the recent advances made in the philosophies of rationality and action. Inspired by these I will defend a non-psychologism according to which emotions are responsive to facts which are the objects of their cognitive components. These facts are the reasons the emotions are had for and they thereby determine the appropriateness of the emotions. This entails that the role of a belief in an emotion is determined by its object.

Thus I will run a second defence of A3, A2 and A1. I will emphasize that tensed and tenseless beliefs play different roles in justifying emotions, A2. I will support A3 by adopting a non-psychologism in regard to reasons for emotions and in doing so I will advance the philosophy of emotions by bringing it into dialogue with the philosophies of rationality and action. I will defend A1 on the basis that our emotions often appear appropriate and if they are not, ...