Elon Musk evidently has a diabolical view of environmental, social and corporate governance – more commonly referred to as “ESG.”

His comments came in response to a Sunday Twitter post from small business expert and advisor Carol Roth.

“Remember when @ElonMusk wanted to bring free speech to Twitter and then S&P removed Tesla from their ESG 500 index, but kept in Exxon?” Roth wrote. “ESG is business social credit. It’s a means to control capital, keep business people in line with the narrative, and, ultimately, control you.”

In characteristically brief fashion, Musk responded: “ESG is the devil.”

ESG refers to non-financial standards used by asset managers and investors in financial decision-making. ESG investing is sometimes referred to as sustainable investing or impact investing, and investors can use ESG standards and criteria to screen potential investments and monitor non-financial risks.

Earlier this year, Tesla was removed from the S&P 500’s ESG index. S&P Dow Jones Indices’ senior director and head of ESG indices Margaret Dorn said in a May blog post that Tesla was no longer eligible for inclusion in the index because its S&P DPJ ESG score had fallen into the bottom 25% of its global industry group peers despite remaining “fairly stable” year over year.

Factors that contributed to Tesla’s lower score include its lack of “low carbon energy and codes of business conduct.”

“While Tesla may be playing its part in taking fuel-powered cars off the road, it has fallen behind its peers when examined through a wider ESG lens,” Dorn said.