A difficult term to explain in a brief note, but I’ll try anyway.
Phenomenology is a philosophical approach that aims to move away from the subject-object division that pervaded modern philosophy and science prior to the 20th century.
That trend tended to be concerned with ‘objective’ knowledge - knowledge of the object apart from the subject. For example, think about water. If we want to gain an ‘objective’ understanding of water, we might start by describing its molecular make up (H2O), or its viscosity and mechanics.
What about the ‘wetness’ of water? ‘Wetness’ only appears as a property of water in relation to some kind of being (e.g., a human) who has the capacity to sense this wetness. Even though we can’t really say that the ‘wetness’ fully comes from the experiencing subject (the human), we also can’t really say that it is a fundamental property of water. It we really want to understand water in its most objective sense, we need to strip away these secondary properties (wetness), i.e., consider water apart from its relationship to a world.
A world can be understood as a living, evolving set of relations. Phenomenology starts by returning to the things themselves (as opposed to the things-in-themselves). Things as pieces and actors within a world, as opposed to objects in a vacuum. There are no subjects and objects ‘in’ a world; subjects and objects are constructs we have developed to help us carve up the world into digestible pieces. But, there is another way we could have done this, another kind of method.
The phenomenological method consists in ‘bracketing’ the sorts of conceptual concerns that shape our understanding of the world in terms of subjects and objects. I am not ‘Mark’ (subject) walking on ‘grass’ (object) in my bare feet, instead, we could simply say an experience of softness/roughness/coldness is occurring. It happens to be occurring at an infinitesimal series of points between different ’things’ in the world (blades of grass, soles of feet). Perhaps the experience is pleasurable, perhaps it is irritating. This isn’t the best example, but the point is that phenomenology starts with descriptions of experience and builds conclusions out from that. If you think about it, this is a very different approach that beginning with some kind of theory or concept of how things should work, and then trying to apply it.
Whereas objectifying accounts of the world want to say that logic, forms, etc. are the primary building blocks of reality - and therefore that particular manifestations of these forms aren’t as integral to the meaning of something - phenomenology begins from the other direction; particularities, experience - all the ‘messiness’ of the actual world - are the foundation of knowledge, and everything else has to begin there.
Now, that is not to say that the ‘mind’ or formal questions play no role. In fact, there is a formal schema that replaces the subject-object division: noesis-noema. After all, the world is not simply a collection of ’experiences’, there are also ‘experiencers’ - agents who interact with the world. And there is a constant kind of relation between experiencers and things - intentionality. Intentionality is the ‘directedness’ of an actor. For example, when I look at that building, there is an intentional relation between me and the building. This intentional relation is noesis. However, when I view the building, from my particular vantage point, I never perceive the entirety of the thing. The part or section of the thing that appears to me (is ‘constituted’) is the noema.
When we think about the world in terms of intentional relations between ’things’, where only one part of the thing is being experienced at any given moment, then we see how the world is an ever-shifting kaleidescope of perception. It makes building a comprehensive ’theory of everything’ pretty difficult…but isn’t that the point?