As a result [I now hold that] the existences ( wujudat ) are primary realities...

As a result [I now hold that] the existences ( wujudat ) are primary realities, while the quiddities are the 'permanent archetypes' ( a'ydn thabita ) that have never smelt the fragrance of existence.10 By taking the position of the primacy of existence, Mulla Sadra was able to answer the objections of Ibn Rushd and the illuminationists by pointing out that existence is accidental to quiddity in the mind, in so far as it is not a part of its essence.

An implication of Mulla Sadra's theory of reality and existence being identical is that existence is one but graded in intensity; to this he gave the name tashkik al-wujud (systematic ambiguity).11 According to Sadra, existence can be conceived of as a continual unfolding of existence, which is thus a single whole with a constantly evolving internal dynamic. Reality to him is ever-changing. The imagined 'essence' gives things their identities.

It is only when crucial points are reached that one perceives this change and new essences are formed in our minds, although change has been continually going on. Due to this 'infinite diversification', the so-called realm of 'immutable essences' does not exist for Mulla Sadra.12 Time, in his view, is the measure of this process of renewal; it is not an independent entity where events take place.

Rather, it is a dimension exactly like the three spatial dimensions - the physical world thus is a spatio-temporal continuum. This theory permitted Mulla Sadra to give an original solution to the problem of the eternity of the world which had continually pitted philosophers against theologians in Islam.

In his system, the world is eternal as a continual process of the unfolding of existence but since existence is in a constant state of flux due to its continuous substantial changes, every new manifestation of existence in the world emerges in time.

The world, that is, every spatio-temporal event from the highest heaven downwards, is thus temporally originated, although as a whole, the world is also eternal in the sense that it has no beginning or end, since time is not something existing independently within which the world in turn exists. Sadra conceived hikma (wisdom) as 'coming to know the essence of beings as they really are', or as 'a man's becoming an intellectual world corresponding to the objective world'.

Philosophy and mysticism, hikma and Sufism, are for him two aspects of the same thing.