Text Kuhn
Revolutions as Changes of World view

Paradigm changes cause scientists to see the world of their research-engagement differently.
As their only recourse to that world is through what they see and do, we may want to say that after a revolution scientists are responding to a different world.

At times of revolution, when the normal-scientific tradition changes, the scientist’s perception of his environment must be re-educated in some familiar situations he must learn to see a new gestalt.
After he has done so the world of his research will seem, and hence there, incommensurable with the one he had inhabited before.

A paradigm is prerequisite to perception itself.
What a man sees depends both upon what he looks t and upon what his previous visual-conceptual experience has taught him to see.
In the absence of such training there can only be ‘a bloomin buzzin’ confusion.

The scientists can have no recourse above or beyond what he sees with his eyes and instruments.
If there were some higher authority by recourse to which his vision might be shown to have shifted, then that authority would itself become the source of his data, and the behaviour of his vision would become a source of problems.
In the sciences, if perceptual switches accompany paradigm changes, we may not expect scientists to attest to these changes directly.

Even the most striking past success provides no guarantee that crisis can be indefinitely postponed.
Even though the world does not change with a change of paradigm, the scientist afterwards works in a different world.

What occurs during a scientific revolution is not fully reducible to a reinterpretation of individual and stable data.

• The data are not unequivocally stable
  The data that scientists collet are themselves different
• The process by which either the individual or the community makes the transition is not one that resembles interpretation
  Rather than being an interpreter, the scientists who embraces a new paradigm is like the man wearing inverting lenses.
  Confronting the same constellation of objects as before and knowing that he does so, he nevertheless finds them transformed through and through in many of their details

An interpretive enterprise can only articulate a paradigm, not correct is.
Paradigms are not corrigible by normal science at all.
Instead, normal science ultimately leads only to the recognition of anomalies and to crises
These are terminated, not by deliberation and interpretation, but by a relatively sudden and unstructured event like the gesalt switch.

The operations and measurements that a scientists undertakes in the laboratory are not ‘the given’ of experience but rather the ‘collected with difficulty’.
They are not what the scientist sees, at leas not before his research is well advanced and his attention focussed.
They are the concrete indices to the content of more elementary perceptions, and as such they are selected for the close scrutiny of normal research only because they promise opportunity for the fruitful elaboration of an accepted paradigm.
Operations and measurements are paradigm-deterimined.

Only after experience has been thus determined that the research for an operational definition or a pure observation-language can begin.