This unassuming question, which is nevertheless one of the most complex we are ever likely to encounter, lies at the core of psychotherapy. Who we are, and how we deal with our experiences, forms the basis of any form of self-development, whether we are seeking help for a particular problem, or simply curious to find out more about ourselves.

From its earliest inceptions psychotherapy has been concerned with people's thoughts, behaviours and feelings, and how these are interlinked. Cognitive Behavioural Therapy is currently popular, because it offers a time-limited structure which is attractive to people with a limited budget. It is evidence-based and often shows good, quantifiable results, and the premise is simple: if there is a behaviour you want to change, change the thought that leads to that behaviour.

But where do our thoughts come from? No one really knows, because no one knows exactly what a thought is. Two people experiencing the same situation won't have identical thoughts about it, because they are individuals, seeing the event only from their own perspective.

One connection we can make is that the thoughts we have about an event, person or object are influenced by the way we feel about it: if someone makes us feel uneasy, our thoughts are more likely to be unfavourable, whereas the sight of fluffy kittens playing will probably invoke positive thoughts and feelings.

Differences of opinion lead to conflict, no matter how good natured the tolerance or catastrophic the consequences.

This is a neat connection, but I don't think it goes far enough. If feelings are the trigger for thoughts, where do the feelings themselves come from?

How we feel about a given situation is governed by a deeper level of our psyche: our beliefs. These may be religious or spiritual, political, social or personal, but each of us has our own, individually developed framework of beliefs. Some people would call it conscience, or a moral compass. It is the part of us that tells us what is right and wrong, and it is from this that all our feelings, thoughts and behaviours develop.

So, we have a nice, straightforward model here: beliefs lead to feelings; feelings to thoughts; thoughts to behaviours.

Of course, this is only straightforward until another factor is taken into account: something that is central to humankind, and arises from the fact that we are all individuals with different beliefs, feelings and thoughts. This factor is conflict.

Any news story, novel, film, debate or complaint boils down to conflict. Conflict between countries, between people, between political parties, between humankind and nature; all point to one fact: differences of opinion lead to conflict, no matter how good natured the tolerance or catastrophic the consequences.

Psychotherapy is about sorting out the tangles that conflict causes in our progression from beliefs to behaviours.

Conflicts between people make up some of a psychotherapist's caseload, but far more common are issues arising from internal conflicts. Beliefs, feelings, thoughts and behaviours are all our own, and we have responsibility for them, but the correlation between them is not always straightforward. Someone trying to quit smoking tells themselves “just one doesn't matter", but they don't believe this: it is merely an excuse to engage in a damaging but comforting behaviour.

Psychotherapy is about sorting out the tangles that conflict causes in our progression from beliefs to behaviours. In recognising the conflict, and exploring ways to be true to our innermost feelings and beliefs, great strides can be made toward becoming a happier, more content person.