What is truth?
An approach from critical realism
Introduction We live in a time where there are many opinions but few certainties. There are many personal stories and growing cultural relativism. Because of this, the difference between objective truth and subjective truth becomes very important. This essay offers a clear philosophical definition of objective truth, based on the approach of critical realism, and explains why this idea is basically opposite — but not necessarily contradictory — to subjective truth.
Before defining objective truth, let's think about this question: Is truth the same as reality? The quick answer is no, truth and reality are not the same.
Even though in everyday language people often use “truth” and “reality” as if they meant the same, philosophically they are different ideas:
Reality is what IS, no matter what we think, perceive, or believe. It belongs to the order of being, meaning it exists independently. Reality is simply what exists.
Truth, on the other hand, is a property of knowledge or statements, not of things themselves. It belongs to knowing: it refers to what we say or believe about what exists.
So, truth is a relationship between our thinking and reality, not reality itself.
Classical truth The classic idea of truth called adaequatio intellectus et rei — “the agreement of the mind with things” — was defined by Thomas Aquinas following Aristotle. Truth is when what we say agrees with what is.
“To say of what is that it is, and of what is not that it is not, is to say the truth.” — Aristotle, Metaphysics IV.
This idea assumes reality exists independently of us and that we can know it, at least partly. So truth depends on how accurately we describe reality, but truth is not the same as reality.
Subjectivity and Mediation With the rise of modern philosophy (Descartes, Kant), the subject — the thinking person — became central. Kant said we don’t know the “thing-in-itself” (noumenon), only its appearance to us (phenomena), shaped by the mind’s built-in structures like space and time.
This brings a more nuanced view:
Reality in itself remains partly unknowable (objective).
Truth is constructed through our ways of perceiving (subjective).
Later thinkers like Nietzsche and cognitive constructivists (Piaget, Varela, Maturana), and hermeneutic philosophers (Gadamer, Ricoeur), deepened this idea: all truth is influenced by interpretation, history, language, culture, and mental frameworks.
So, what is truth? Some modern and contemporary definitions:
Critical realism (Bhaskar, Popper, Searle): Objective truth is possible when our theories closely describe an independent reality, even though our knowledge is always provisional and can be corrected.
Coherence theory (Bradley, Hegel): Truth is about internal consistency within a system of beliefs; it doesn’t have to refer to external reality, just be logically consistent.
Pragmatic theory (James, Peirce, Dewey): Truth is what “works” — what solves problems or stands the test of time.
Perspectivism (Nietzsche, Ortega): All truth is a perspective; there is no absolute truth, only different depths of interpretation depending on experience and the observer.
Truth and reality are connected but not the same. Truth is a representation, approximation, or interpretation of reality.
Truth can be:
Subjective: based on personal perception or belief (e.g., “this food tastes good”).
Intersubjective: shared by a community (e.g., “democracy is a fundamental value”).
Objective: aiming to correspond to independently verifiable facts (e.g., “water boils at 100°C at sea level”).
Final thoughts Reality can exist even if no one knows it, but truth cannot exist without a subject who states or thinks it.
Truth is always a cognitive activity — a judgment that tries to represent or explain reality. It is like a mirror that humans raise before reality, but this mirror never fully shows the whole picture. Only fragments of reality appear in truth.