Can we have knowledge based on Naturalism?
Very roughly, naturalism is the view that all that exists is natural, which usually is explained in terms of the physical; there are no supernatural entities. Now, Daniel Dennett is a naturalist and a leading philosopher of neuroscience. He denies there are any real, immaterial, “mental” states (e.g., thoughts, beliefs, desires). Nor is there any real intentionality, the "ofness" or aboutness of mental states (Dennett 1994, 239).
Let me explain intentionality more. For many, it is a property of thoughts, beliefs, observations, concepts, meanings, and more. It seems these always are of or about something, even if that thing does not obtain in reality (e.g., Pegasus). I can think of Pegasus, even though there isn’t a winged horse. So, it seems intentionality would not be physical. If it were, it seems that having a thought about something would require that thing exists in order to physically cause that thought in me.
Instead, for Dennett, natural selection is a blind process without any intentionality, goals, or real thoughts (e.g., Dennett 1990, 318). There is only physical stuff, including brains that process our sensory inputs. There are just brain states, patterns of physical forces, and behavior that we take (or interpret) to be about something, though they really aren’t (Dennett 1990, 40). These interpretations are the results of many of the brain’s distributed “takings.”
Consistently as a naturalist, Dennett also denies any essences exist. But, if they did, they would be something non-physical that’s true of something (e.g., a person, a thought, or a meaning) just because of what kind of thing it is - i.e., due to its essence. If real, Dennett says there could be a “deeper fact” beyond just behavior of what our thoughts (or beliefs, experiences, etc.) are really about (Dennett 1990, 319, note 8).
However, since they are not real, we are left with just interpreting behavior by adopting a tactic he calls the intentional stance (IS). Using it, we treat a frog, human, or chess-playing computer as if it were an intentional system. The IS is “the tactic of interpreting an entity by adopting the presupposition that is an approximation of the ideal of an optimally designed (i.e. rational) self-regarding agent” (Dennett 1994, 239). We attribute intentions to the thing, to help predict its behavior.
Now, Dennett admits that if intrinsic essences were real, there could be real, intrinsic meanings to behaviors such as speech, writings, and gestures. He also recognizes the importance of Jacques Derrida’s deconstructionism, which also denies essences. Without an intrinsic meaning in the text, its meaning is just our interpretation. Likewise, for Dennett, thoughts and speech are brain-writings, which are subject to interpretation, just like any other text (Dennett 1990, 40).
What then should we make of naturalism’s claims about the objectively real world being physical, that we are just our bodies, and that naturalism is true? At best, these are nothing but interpretations. Indeed, all our scientific observations and all our beliefs are just interpretations. But, of what? If everything is interpretation, we seem to face an infinite regress, without a way to even get started with accessing reality itself.
Additionally, interpretations also seem to be of or about something. That is, they too seem to have intentionality. Yet, without that being real, there are no interpretations. So, it seems that on naturalism (and not just Dennett’s version), there are not even any interpretations, or conceptualizations. However, without concepts, there are no beliefs, for beliefs require concepts. And without beliefs (which also are about things), there is no knowledge of the facts of reality. That knowledge is justified true belief – but without beliefs, there is no knowledge. So, naturalism cannot give us knowledge.
Nevertheless, surely there are many things about reality that we do know. Thus, naturalism must be false.
Dennett, Daniel. “Dennett, Daniel C.” In A Companion to the Philosophy of Mind: Blackwell Companions to Philosophy, 236-43. Edited by Samuel Guttenplan. Oxford: Basil Blackwell, 1994.
______. The Intentional Stance. 3rd printing. Cambridge: MIT Press, 1990.
Scott Smith, Ph.D. is Professor of Christian Apologetics at Talbot School of Theology, Biola University.
For Professor Smith's full treatment of this topic:
R. Scott Smith, Naturalism and Our Knowledge of Reality: Testing Religious-truth Claims
More of Professor Smith's works