In Greek philosophy, (Plato), aporia means a moment of indecision, bewilderment; as Socrates will converse with someone and get them to realize that they do not understand the concept of which they are speaking. Socrates leaves his conversant in an aporia; not knowing the concept they thought they knew (i.e., love) but being in this aporia, Socrates’ pupil is left with the desire to investigate the concept.
In Post-structuralism and deconstruction, the aporia or “gap” is understood not as a connective, abstract something between words and their meanings. It is, more like the Greeks concept of uncertainty about a concept. For theorists like Derrida, an aporia is a moment of unending undecidability about a concept. This is part of his general deconstructive philosophy that all meaning is always already deferred. Since the signifier (word “tree” ) is not the meaning itself (concept or actual tree), the signifier is not the present meaning; it supplements or substitutes for the tree. Our signifier “tree” is thus temporally and spatially deferred from the presence of its meaning. There is a gap. Now, to understand “tree” we need to know what it is similar to and what it is not; and this could go on forever. (A tree has wood, leaves, it breathes, it is not a flea, etc.) We understand what a tree is by its difference similarity to other signs. So, we get the meaning of the tree through difference and deference (differance). That gap “aporia” of undecidability, where we trace the meaning of the tree is unending. Derrida takes this up a notch by showing how concepts like giving are aporia in that they are paradoxical. A genuine gift implies no recompense, but doesn’t the giver at least have some self-satisfaction even if he expects/wants nothing in return. Derrida shows how the concept of giving is impossible in its possibility. Derrida’s philosophy clearly exhibits the uncertainty he explains.
Aporia are the points of contradiction which deconstruction shows to be inherent in many concepts and in all texts.
An aporia in a Platonic dialogue is a place with no path through (a - poria, note the alpha privative construction). At the end of many of the early dialogues, e.g. Euthyphro, the interlocutors reach an impasse in the discussion, in which they have explored many sides of a question and found no solution. It does NOT mean indecision or bewilderment, and the Platonic use is not the Derridean one.
Aporia comes from the greek word which means puzzlement or confusion.
When you look at someone with a question mark on your face.