Belief and the Blind Man

Painting of a line of blind men leading each other
The blind leading the blind. Oil painting after Pieter Bruegel. Wellcome Library, London (CC BY 4.0)

It may sometimes seem to readers of this blog that too many Irish philosophers of the past were far too interested in religion. However an argument that is first outlined in a religious context may have applications elsewhere.

The thesis of John Toland’s Christianity Not Mysterious is clearly outlined in its subtitle: “A treatise shewing that there is nothing in the gospel contrary to reason, nor above it: and that no Christian Doctrine can be properly call’d a mystery.” Toland’s position is that “reason is the only Foundation of all Certitude” against the Divines who “gravely tell us, we must adore what we cannot comprehend”1. It is impossible, says Toland, to believe what we cannot understand2:

A man may give his verbal assent to he knows-not-what…but as long as he conceives not what he believes, he cannot sincerely acquiesce in it

This is even more the case for the unintelligible or the thing “above reason”. In a famous passage John Toland says 3:

Could that Person justly value himself upon being wiser than his Neighbours, who having infallible Assurance that something call’d Blictri had a Being in Nature, in the mean time knew not what this Blictri was?

However these statements can also apply to science. Why should those who cannot understand it? And why should anyone believe in a theory hinging on something unintelligible? An example at the time of Toland would have been gravity. Newton himself didn’t know how gravity worked, and though his theory assumed its effects were instantaneous, he declared action-at-a-distance with no intermediary to be an absurdity4 For a contemporary example, it’s been said that “if you think you understand quantum mechanics, you don’t understand quantum mechanics” (attributed to Richard Feynman).

John Toland accepted Newtonian physics but rejected key parts of it, such as the concept of void which required action at a distance and the idea of gravity as inherent in all matter. But would it be reasonable to accept Newton’s own conception of his theory?

An answer can be found in a work on religion. In an appendix to a new edition of A Gentleman’s Religion, Edward Synge explicitly answered Toland. Synge believes that though religious mysteries cannot be contrary to reason, they can be beyond it5:

Where a proposition is in itself true, but we are unable clearly to apprehend or frame a Notion or Conception of the things contain’d under the Terms of it, such a Proposition I term to be above Reason. And such a Proposition may be either wholly and altogether beyond our Reason, when we can frame no manner of Conception of the things spoken of; or else but partly above it, when we have some Notions of the things, but those very obscure and imperfect.

Synge uses the metaphor of a man born blind, for whom the ideas of light and colour are entirely above reason, since he can frame no idea of what they might be. Colour and light are less above reason for the partially sighted, whose ideas of them are confused, and not at all above reason for those with normal sight6.

So do we trust what others say they understand to be the truth blindly? Synge argues that no-one can believe anything that seems to be contrary to reason, but she might believe something based on the authority or trustworthiness of a person affirming it (an implicit belief). If she is convinced the person is completely trustworthy she cannot help but think the thing true 7.

A person may be able to give convincing arguments to show they are trustworthy. Synge relates a conversation he had with a man blind from birth. The man had tried to understand the nature of light and asked numerous questions, but despite everything he still had no notion of them 8:

therefore when they told me I was blind, and talked to me of Light and Colours, I apprehended, for a great while, that they did it only to impose on me. But are you now convinced, said I, that you are blind; and that other men have the Faculty of Sight, which you want?…Thus, answered he, was I convinced of it: They would put me at a distance from them, and yet would tell me everything I did; as whether I stood or sat, or held up my Hand or let it down, or the like; Whereas I could not discover any thing which they did, except I were close to them and felt them carefully with my Hands.

Synge argues the belief of the blind man is more than a mere implicit belief. Although he had no direct conception of sight, he could make a representation of “sight” and its powers in his mind. It is more than a meaningless term to him 9.

How successful this analogy is to religion is open to doubt (Synge’s colleague Peter Browne, bishop of Cork, viewed it as being as excessively rationalistic as Toland’s work). It does however demonstrate that, even if we don’t what what Blictri or gravity is, it still may be reasonable to accept its existence, though its ability to predict and explain the otherwise inexplicable world around us.

Further Reading

John Toland (1697/1702) Christianity Not Mysterious, London. (

Alison Morgan (2012) Notes on John Toland – Christianity Not Mysterious (pdf).

Edward Synge (1726) A Gentleman’s Religion, 5th edition, London. (google books)


  1. John Toland (1697/1702) Christianity Not Mysterious, p. 6 and p. 1
  2. Toland (1697/1702), p. 36
  3. Toland (1697/1702), p. 128
  4. Michael Friedman (2012) “Newton and Kant on absolute space” in Andrew Janiak and Eric Schliesser (eds) Interpreting Newton: Critical Essays, Cambridge University Press, pp. 347-8.
  5. Edward Synge (1726) A Gentleman’s Religion, 5th edition, p. 282
  6. Synge (1726), p. 282-3
  7. Synge (1726), pp. 283-5
  8. Synge (1726), pp. 285-7.
  9. Synge (1726), pp. 289-90.
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