The process is always the same.

The individual has a stock of old opinions already.

The individual meets a new experience that puts some of these old opinions to a strain.

• Somebody contradicts them.
• In a reflective moment, the individual discovers that they contradict each other.
• The individual hears of facts with which they are incompatible.
• Desires arise in the individual which the old opinions fail to satisfy.

The result is inward trouble, to which the individual's mind till then had been a stranger.

The individual seeks to escape from this inward trouble by modifying the old opinions.

• The individual saves as many of the old opinions as is possible (for in this matter we are all extreme conservatives).
• Old opinions resist change very variously.
• The individual tries to change this and then that.

Finally, some new opinion comes up which the individual can graft upon the ancient stock of old opinions with a minimum of disturbance to the others.

• The new opinion mediates between the stock and the new experience.
• The new opinion runs the stock and the new experience into one another most felicitously and expediently.

The new opinion is then adapted as the true one.

• The new opinion preserves the older stock of truths with a minimum of modification, stretching them just enough to make them admit the novelty, but conceiving that in ways as familiar as the case leaves possible.
• An outreé explanation, violating all our preconceptions, would never pass for a true account of a novelty.

The most violent revolutions in an individual's beliefs leave most of his old order standing.

New truth is always a go-between, a smoother-over of transitions.

The point I now urge you to observe particularly is the part played by the older truths . . . their influence is absolutely controlling. Loyalty to them is the first principle; for by far the most usual way of handling phenomena so novel that they would make for a serious rearrangement of our preconceptions is to ignore them altogether, or to abuse those who bear witness for them.