One way to translate a fundamental claim of phenomenology into Thomist terms is to say that before Phenomenology, everyone was working from an unrealized negative abstraction from their actual experience of the world.
Thomism developed to recognize several different sorts of abstraction. There were at least two sorts of positive abstraction, sc. the abstraction of a universal whole from its parts (like when we get the idea “placental mammal” by looking at pigs and cows) and the abstraction of a form from the-thing-with-the-form (like when we get the idea of “redness” from “red” or the idea of a circle from looking at a wheel.) Both of these abstractions, however, presuppose the more general reality of negative abstraction, which is simply the act of considering one thing without another. This allows not only for positive abstraction but also the mere act of paying attention or focusing on one thing and letting others fall from consciousness, e.g. we can consider the color of a rose without considering its scent. This sort of “abstraction” is found in any finite cognitive power – a cat focusing on something will tune other things out.
The claim of phenomenology is that pre-phenomenological thinkers all made an unrealized negative abstraction from the world as actually experienced. Experience comes to us as a totality, but science and philosophy all try to start from some part divided from that whole. Aristotle, for example, starts with “substance”. He separates, say, a cow from the field of experience, lets everything else drop from view, and quietly assumes that the world is an enumeration of these substances. But experience does not come to us like this. We see the whole first and then divide it into parts (like “substance”) by various turns of focus. True, if we are to study anything, we need to let this initial totality fall into the subconscious, but this only means that any act of learning involves a submersion of a vast section of the world as it comes to us. This is one application of Heidegger’s idea that every disclosure of being also hides it.
Arguably, by overlooking this initial totality of experience, we have fallen into the idea that analysis is fundamental, or that ultimate reality is the part. Our ontologies are thus all searches for the ultimate part. We seek reality in what is most isolated and cut off from things.