The Walk · 6 of 14
CON-SENSE
What does the mind add to seeing?
Cambridge Platonist. Manuscript c. 1658 to 1663. Print 1678. Posthumous 1731.
1731 · printed after his death
One watch. Three receivers.
Ralph Cudworth holds a watch before a mirror, then a living eye, then asks what the mind adds. They are not three clocks. They are three ways of receiving the same light.
The mirror
Receives.
Shape, color, motion. The same impressions as the eye. It does not know that it reflects.
The living eye
Is aware.
The eye is conscious or perceptive of what it undergoes. Already different from the mirror. Not yet mind.
The mind
What does the mind add to seeing?
Cause. Effect. Means. End. Whole. Part. Sign and thing signified. Relations with no color. Sense would deny they were there.
Ralph Cudworth, A Treatise concerning Eternal and Immutable Morality (London: James and John Knapton, 1731), 150–56. Published after his death. Not 1678. The watch is a diagram of his argument, not a photograph of an eighteenth-century plate.
Source plate · 1678
an inward Consciousness of our own Cogitations
Ralph Cudworth, The True Intellectual System of the Universe (London: Richard Royston, 1678), 159. Self from within. Other minds from actions, motions, speech, effects. Wording after the printed page. This plate is not a photograph of that page.
Hear
English is learning to name awareness apart from rightness. Ralph Cudworth, 1617 to 1688, an English philosopher at Cambridge, did not invent consciousness.
Keep three dates apart.
Around 1658 to 1663, in manuscript work on liberty and necessity, he writes of darkness, light, Plato's cave, an image of prisoners taking shadows for the real, and the opening of the eyes of the soul.
That is theological and moral. It is not a theory of the retina.
In 1678, in The True Intellectual System of the Universe, he gives inner awareness a philosophical English name. We are certain of our own souls, he says, partly from an inward consciousness of our own cogitations.
Other minds we do not see as objects. We infer them from actions, motions, speech, effects.
You cannot see a soul. That does not mean there is nothing there.
In 1731, after his death, A Treatise concerning Eternal and Immutable Morality is printed. There a watch is held before a mirror and a living eye.
The mirror receives shape, color, motion, and knows nothing of it. The eye receives the same, and is perceptive of what it undergoes.
The mind goes further. It apprehends cause and effect, means and end, whole and part, sign and thing signified.
What does the mind add to seeing? The question can wait.
Consciousness here is doing work in a theory of agency and responsibility. Morality has not left the building.
Documented
c. 1658 to c. 1663. Opening the eyes of the soul.
In manuscript material on liberty and necessity, Cudworth uses darkness, light, and Plato's cave. The soul must turn.
The eyes that open are not laboratory eyes. This is theological and moral, not a theory of the retina.
Manuscript dating is a scholarly reconstruction. The public printed date of the later Treatise is 1731.
Primary text
1678. You cannot see a soul.
In The True Intellectual System of the Universe, Cudworth writes of an inward consciousness of our own cogitations. The soul is not visible as a bodily object.
Self is known partly from within. Other minds are known from actions, motions, speech, and effects.
This is a major historical ancestor of the other-minds problem. It is not modern cognitive science.
Primary text
1731. Mirror, living eye, mind.
A Treatise concerning Eternal and Immutable Morality is published after Cudworth's death. The watch argument belongs to this book, dated 1731, not to the System of 1678.
A watch is held before a mirror and a living eye. The mirror receives impressions and knows nothing.
The eye is conscious or perceptive of what it undergoes. The mind, superadded, compares parts of the machine and raises ideas of cause, effect, means, end, order, proportion, sign and thing signified, whole and part.
Sense would deny those relations, because they have no color.
Scholarly interpretation
The word serves agency
He still translates Plotinus's synaisthēsis as con-sense, or consciousness. Grades of awareness remain.
Plastic natures operate without express consciousness. Free action needs the ruling principle to have cognisance of the soul's powers.
Awareness is bound to self-direction. Conscience did not vanish when consciousness arrived.
Limit
What this does not prove
It does not prove that Cudworth invented experience. It does not turn a theological turning of the soul into a theory of the retina.
The three dates remain three.
Open question
What does the mind add to seeing?
The question returns later, under other names. Recurrence is not descent.
The question here remains his: what does the mind add to seeing?
The question returns. Other minds
Sources
Cudworth, Ralph. The True Intellectual System of the Universe. London: Richard Royston, 1678.
Translates Plotinus's synaisthēsis as con-sense or consciousness. Distinguishes grades of awareness and allows mental activity that is not fully conscious.
Plastic natures operate without express consciousness.
Cudworth, Ralph. A Treatise concerning Eternal and Immutable Morality. London: James and John Knapton, 1731.
Published posthumously. The mirror and eye argument is 1731, not 1678.
A watch is held before a mirror and a living eye. The mind superadded apprehends relations (cause, effect, means, end, whole, part) that sense and the mirror do not.
Plotinus. Enneads. c. 250–270.
Synaisthēsis, co-perception or inner sense of the soul. Source material later received by Cudworth.
Plotinus did not possess the modern English concept.
Hutton, Sarah. “Ralph Cudworth.” Stanford Encyclopedia of Philosophy. consulted 2026.
Cudworth's con-sense, plastic natures, free will, and moral philosophy. Warns against treating the published System as a complete ethics.
Hutton, Sarah. “Ralph Cudworth.” Stanford Encyclopedia of Philosophy. 2024.
Dates the watch illustration to TEIM 85–6 in modern pagination. Distinguishes the 1678 System from the posthumous Treatise.
Leisinger, Matthew. “Essays on Cudworthian consciousness and agency.” 2019–2022.
Cudworth's grades of consciousness, the hegemonikon, and the work the word was doing in a theory of agency.