Water is the element of emotion and the unconscious, as opposed to the conscious intellectualism of air. Water is one of two elements that have a physical existence that can interact with all of the physical senses. Water is still considered less material (and thus superior) to earth because it possesses more motion and activity than earth.
Earth is the element of stability, groundedness, fertility, materiality, potential, and stillness. Earth can also be an element of beginnings and endings, or death and rebirth, as life comes from the ground and then decomposes back into earth after death.
Air is the element of intelligence, creativity, and beginnings. Largely intangible and without permanent form, air is an active, masculine element, superior to the more material elements of water and earth.
Fire is associated with strength, activity, blood, and life-force. It is also seen as highly purifying and protective, consuming impurities and driving back the darkness. Fire is traditionally seen as the most rarefied and spiritual of the physical elements because of its masculine properties (which were superior to female properties). It also lacks physical existence, produces light, and has a transformative power when it comes in contact with a more physical material.