When disciplines lose confidence

Increasingly I hear talk about how different academic disciplines have lost confidence in their identity, autonomy, and legitimacy. They are "in crisis", "have an uncertain future", or "need to re-invent themselves". These concerns range from physical chemistry to political science. For example, yesterday I heard a talk along these lines from David Armitage, Chair of the History Department at Harvard.

Generally, I think this anxiety is bad for the discipline and is often for the wrong reasons.
Furthermore, those who stay the course will ultimately be successful. Those who get caught up in the latest soul searching re-invention will dissipate their energies on some passing fad.

Why do people loose confidence in their discipline and the value of what they are doing?

A. Unhealthy comparisons with other disciplines and jealousy. The rates of advance of knowledge vary across disciplines and at different periods of time. There may be a decade where one discipline will see some stunning advances where another will just "plod along".
This pressure to be as "successful" as other disciplines is sometimes measured in superficial terms such as funding levels, student numbers, department size, shiny new buildings, ....

B. Disillusionment sometimes occur when the discipline does not live up to the hype of some research area.
Cosmology hasn't told us "why we are here." The Human Genome Project has not cured diseases. There is no quantum computer with hundreds of qubits. Fusion power is still 30 years away...  Previously, I posted about how Marcelo Gleiser became disillusioned with high energy physics because it did not live up to its reductionist propaganda.

C. Pressure to be a "service industry" for other disciplines. Currently, some biologists seem to think that physics and chemistry should play this role for them, i.e., providing instrumentation, techniques and tools, not concepts and theories. The attitude and issues are embodied in the 1997 Physics Today article "Harnessing the hubris: useful things physicists could do in biology" by V.A. Parsegian and the rebuttal by Bob Austin.

Previously, I posted Ahmed Zewail's persuasive arguments for the value and distinctness of chemical physics.

Why do I think disciplines are valid and will endure?
It is because they reflect the stratification of reality. The consequent autonomy of disciplines is nicely discussed in Phil Anderson's classic, More is Different.

In the humanities, in the first half of the twentieth century, the theologian Karl Barth resisted the pressure to reduce theology to other disciplines such as sociology, history, anthropology, philosophy, ... His colleagues who succumbed have now mostly been forgotten. Elsewhere I explore Barth's resistance to reductionism.