In order to understand futures research, it is necessary to have different notions of possibility at hand. In what follows, I identify different notions of possibility and explain what I mean by them and why I think they deserve to be identified. In other words, I provide one way to understand different notions of possibility.

Predictable. By predictable, I mean an event (or a state of affairs or a trend; does not matter here) that follows straightforwardly from the current situation and a set of generalizations that govern the domain at hand and are not expected to change before the event. Moreover, predictability requires that we have epistemic access to the relevant determinants of that future events. We do not have to know the determinant but it must be the case that we would know them if we paid attention to them.

Predictable should not be equated with inevitable or necessary. These are stronger notions. An event can be predictable while not inevitable: to be inevitable, an event must occur even if the initial conditions were different. Predictable events do not need to have this property. It is enough that they follow, given the actual situation.

The notion of predictable deserves to be identified since, arguably, what we can predict is the most clear-cut case of knowledge about the future. Moreover, the ability to say something about the future by following where the current situation leads is a kind of canonical case of future methodology that serves as an exemplar when we construct methodologies of knowing other types of possibilities.

Plausible. By plausible, I mean an event that follows from a credible set of generalizations and a credible description of the current situation. What we consider as credible generalizations and descriptions may not match the reality, but we have good reasons to believe that they are true (or, at least, to be trusted).

Plausible deserves to be identified, as it is the notion that captures the type of knowledge about the future that is not quite certain but credible enough. Plausible captures a reflective attitude toward the future where we believe in certain future events after we have assessed the credibility of the sources of knowledge and admitted their limitations to some extent. This reflective attitude and surrendering to limitations in our knowledge serves as an exemplar to other notions where our confidence towards the knowledge of the future is lower.

Possible. By possible, I mean an event that either (i) is not in contradiction with what we know, or (ii) follows from an internally coherent and somewhat credible set of generalizations and description of the current situation. Obviously, plausible and predictable events satisfy these criteria and therefore count as possible events. However, possible demand less than plausible or predictable.

Possible deserves to be identified, as it serves as a general category that includes many other notions of possibility. Moreover, possible opens the door to the idea that the future might involve something we do not find credible and, therefore, we need to be prepared for different types of futures and make scenarios of them. Possible serves as an exemplar to other notions that force us to be open to different types of futures.

Alternative. By alternative, I mean an event that goes against what we believe and value. Whereas possible forces us to consider many different futures, alternative makes this a value in itself. An alternative future is a future that follows when we question our knowledge and values and ask “what if we are wrong”.

Alternative deserves to be identified, as it captures fundamental uncertainties in the knowledge of the future and the value-ladenness of our ideas concerning the future. It crystallizes the critical tenets of futures research and the tenets to critically reflect on the conceptions that shape our understanding of the future.

Desirable. By desirable, I mean a future that we find valuable and ethically sound. A desirable future needs to be a possible future, otherwise it becomes an obsolete utopian scenario.

Desirable deserves to be identified, as it explicitly captures the ethical component of futures research. It underlines the fact that we can shape the future and we can shape it for better or worse. Desirable also serves as a contrast to scenarios that follow when we distance ourselves from our current values. Desirable futures underline the fact that the ethical judgments about the future are made by us, different (alternative) futures follow if different values are at play.

Conceivable. By conceivable, I mean an event that is (i) conceptually and ontologically coherent, (ii) and can be known by some means and reasoned about. Conceivable events do not need to be possible events. They do not need to be credible and they can be in contradiction with what we know. Conceivable futures, therefore, include all the futures that can be thought of.

Conceivable deserves to be identified, as it marks the limits of all the possible knowledge about the future. Outside this realm, there are inconceivable futures. These futures we cannot think of or reasons about even though some of them might be objectively possible (see Virmajoki 2022, “Limits of Conceivability”).

We should notice that conceivable events do not include all events that one can form some sort of a mental image. We can imagine all sorts of scenarios that we cannot make sense of in any detail. For example, one might speculate that, in the future, all existing knowledge is proved to be wrong. This might be the case, but we cannot conceive it, as there is no way to reason about what happens in that future: the reasoning would be based on our knowledge which is, by definition, wrong in the scenario. Take another example: One might imagine that we invent a way to turn me into a cat. However, it is not ontologically or conceptually possible that I become a cat; whatever my identity is, it is lost when I turn into a cat.

This points toward the final observation: Not everything that can be asserted and imagined deserves to be understood in terms of the notion of possibility. We should tie the notion of possibility down to methodological steps that can be taken in futures research.