So why then is the Mental Universe so important and what does it offer the individual who understands its significance?
The element of subjectivity is essential to appreciating the Mental Universe. As each person and living being has its own unique perspective on existence it is the synchronicity of these perspectives which condition our own personal Universe.
Of course, not every living creature has the capacity to choose to what extent, if at all, it can contribute to the condition of the Universe and this argument can even be extended to the human capability of Free Will. After centuries of argument between Determinism and Free Will suffice it to say that the debate is most satisfactorily resolved with the choice of accepting or refuting destiny: I can decide to vote or not to vote, but my choice of candidate has probably been determined by the sum of my living experiences and exposure.
Having briefly side tracked and, hopefully, successfully contented the argument of subjective responsibility the importance of the Mental Universe results in life's greatest value: Happiness. It is the oldest of sayings that money can't buy Happiness and time flies when you're having fun, but it is in the last thirty years or so that its true value has started to become apparent. Happiness is being transformed from an ontological ideal to a qualitative measure of life. We are beginning to realise that those who are most successful at living are not the richest or most powerful but the happiest and that the mistaken longing of riches and power are the sure road to misery. The most effective way to assure one's Happiness is to follow the mantra written centuries ago above the entrance to the temple of Apollo in Delphi: Know thyself.
To know oneself is to have the knowledge of one's subjectivity. To be intimately acquainted with one's own desires, capabilities, weaknesses, awareness and surroundings is to be in touch with the Mental Universe. The greatest and inevitable consequence of this knowledge for humanity is the effect it has on the other. Arguably the greatest asset homo sapiens possess is social psychology. It is this capacity called theory of mind which has allowed humanity, for better or for worse, to dominate the planet. Humans are the animals of this planet that benefit the most from social interaction to the very point that it is fundamental to the goal of a successful life: Happiness.