Epiphenomenalism suffers from quite a few logical flaws.

For one, it contradicts Newton's law of reaction, in that it implies that there could exist cases where causation is asymmetric and non-reversable: X can cause Y but Y cannot cause X. To my knowledge we have yet to find any evidence of such asymmetric causation in nature. What seems to be the case is that if X can impact Y, then Y can impact X, at least in principle. Causality works both ways.

More fundamentally, something that exists as part of this world must exist in some sense as a cause for something else. It must make a difference in this world, otherwise in what sense is it part of it? How could we even ascertain its existence? How could we notice it?

Epiphenomena do not exist, as defined. They have no way of existing, other than as a figment of our imagination, because to exist means to impact other stuff around.

Finally, as a specific biological behavior, conscious thoughts require a Darwinian explanation as per how they emerged, and why they spread and remained a character of a certain population of living organisms throughout a certain evolutionary period. By definition, an epiphenomenon can present no Darwinian advantage, so how come we are not all unconscious beings?

Conscious thoughts must present an advantage to the organism, least they contradict Darwin.

Epiphenomenalism contradicts what we have learned concerning nature, through such people as Newton and Darwin.

It contradicts Newton's law of reaction, in that it implies that there could exist cases where causation is asymmetric and non-reversable: X can cause Y but Y cannot cause X. To my knowledge we have yet to find any evidence of such asymmetric causation in nature. What seems to be the case is that if X can impact Y, then Y can impact X, at least in principle. Causality works both ways.

More fundamentally, something that exists as part of this world must exist in some sense as a cause for something else. It must make a difference in this world, otherwise in what sense is it part of it? How could we even ascertain its existence? How could we notice it?

Epiphenomena do not exist, as defined. They have no way of existing, other than as a figment of our imagination, because to exist means to impact other stuff around.

Finally, as a specific biological behavior, conscious thoughts require a Darwinian explanation as per how they emerged, and why they spread and remained a character of a certain population of living organisms throughout a certain evolutionary period. By definition, an epiphenomenon can present no Darwinian advantage, so how come we are not all unconscious beings?

Conscious thoughts must present an advantage to the organism, least they contradict Darwin.

Epiphenomenalism suffers from quite a few logical flaws.

For one, it contradicts Newton's law of reaction, in that it implies that there could exist cases where causation is asymmetric and non-reversable: X can cause Y but Y cannot cause X. To my knowledge we have yet to find any evidence of such asymmetric causation in nature. What seems to be the case is that if X can impact Y, then Y can impact X. Causality works both ways.

More fundamentally, something that exists as part of this world must exist in some sense as a cause for something else. It must make a difference in this world, otherwise in what sense is it part of it? How could we even ascertain its existence? How could we notice it?

Epiphenomena do not exist, as defined. They have no way of existing, other than as a figment of our imagination.

Epiphenomenalism suffers from quite a few logical flaws.

For one, it contradicts Newton's law of reaction, in that it implies that there could exist cases where causation is asymmetric and non-reversable: X can cause Y but Y cannot cause X. To my knowledge we have yet to find any evidence of such asymmetric causation in nature. What seems to be the case is that if X can impact Y, then Y can impact X, at least in principle. Causality works both ways.

More fundamentally, something that exists as part of this world must exist in some sense as a cause for something else. It must make a difference in this world, otherwise in what sense is it part of it? How could we even ascertain its existence? How could we notice it?

Epiphenomena do not exist, as defined. They have no way of existing, other than as a figment of our imagination, because to exist means to impact other stuff around.

Finally, as a specific biological behavior, conscious thoughts require a Darwinian explanation as per how they emerged, and why they spread and remained a character of a certain population of living organisms throughout a certain evolutionary period. By definition, an epiphenomenon can present no Darwinian advantage, so how come we are not all unconscious beings?

Conscious thoughts must present an advantage to the organism, least they contradict Darwin.