(for the uninitiated)
1. a necessity. See Grant, R (2014, Oct 21). "Philosophy in our schools a necessity, not a luxury." Irish Times. In post-truth society where appeals to emotions and personal beliefs trump objective facts in shaping public opinion, philosophy provides the tools needed to enable citizens “to discriminate between truthful language and illusory rhetoric” (Humphreys, 2016).
Philosophy is necessary for asking the right questions.
"The study of philosophy cultivates a healthy scepticism about the moral opinions, political arguments and economic reasonings with which we are daily bombarded by ideologues, churchmen, politicians and economists. It teaches one to detect ‘higher forms of nonsense’, to identify humbug, to weed out hypocrisy, and to spot invalid reasoning. It curbs our taste for nonsense, and gives us a nose for it instead. It teaches us not to rush to affirm or deny assertions, but to raise questions about them.
"Even more importantly, it teaches us to raise questions about questions, to probe for their tacit assumptions and presuppositions, and to challenge these when warranted..." (Hacker, P. (2013, Dec 10). "Why Study Philosophy?" IAI News)
2. Philosophy is also needed to avoid disciplinary capture, for instance, in science (Briggle & Frodeman 2016), medicine (Smith, 2016), engineering (Boyd, 2014).
3. Eventually you'll end up with Philosophy. You may search high and low, far and wide, and your search is likely going to end up in Philosophy.
Screengrab from BBC (2016), "The Joy of Data"
Here's your "proof."