Reason is attention to the relationships between things — what things signify. Attention brings the relationships into existence. Relationships that dissolve under attention are found not not to exist.

Reason attends to the consistency and coherence of relations between things — do they make sense together?

Reason is a drive toward making sense of the world, toward meaning. Reason connects the small with the great, parts to whole, cells with organism, past with future, imparting significance.

Reason is the measure of existence.

...if you use a ruler to measure a table you may also be using the table to measure the ruler. The less you trust the ruler’s reliability, the more information you are getting about the ruler and the less about the table. (Taleb 2005)

Reason, a distilled form of attention, leads to the scientific paradigm shifts described by Thomas Kuhn. A manifestation of love, it can also lead from religion to atheism. (A new paradigm does not necessarily make the old obsolete. For example, quantum physics replaced classical Newtonian understandings of the laws of the universe, but we still rely on classical physics when we want to build an apartment block.)

Like a magnifying glass, reason reveals hidden relationships. It also creates new relationships by putting the observer in a new perspective with the observed.

Reality sits between moments. It is the relationship between moments, connecting past and future. Attempts to capture reality — to fix it in a moment — lose its relational essence. Any "now" has already past. Of no moment, reality is momentum.

Reality is the solution to Zeno's paradox of Achilles and the Tortoise.