>To mature as a species, we need to embrace a perspective called longtermism – a way of thinking that differs greatly from the prevalent mindset today.

Interest rates effectively reflect how short term or long term oriented people are, they are supposed to balance consumption and investment in such a way that consumption in the future is maximized. The lower the interest rates the more future oriented people are, the the higher the interest rate, the more present oriented people are. So from this perspective the demand to think about the long term today is irrational, a high interest rate means there are short term needs that haven't been met and that there are no resources available that can be committed toward the long term future.

What this also means is that any lower bound on interest rates acts as a barrier to how future oriented people are, it acts as a barrier to long term thinking because when interest rates go to zero, the short and the long term rate differences start compressing and disappearing, leading to excessive demand for short term investments. So if the rate on a long term bond must be zero, the rate on short term bonds must be negative just to maintain the shape of a steep yield curve that rewards long term investments.

In the extreme case of deflation, rates may have to be negative just so real yields can be 0%. If the real yield isn't adjusted back to zero, then deflation effectively raises real returns on liquid demand deposits and cash which are both very short term savings. This means deflation drives people to become very short term oriented just because of a flaw in the monetary system. This is why ending a recession or depression early actually has long term benefits to an economy because simply continuing the economy as if there is no recession means that people don't start liquidating and closing down businesses too early when it turns out that those very same businesses are needed three years later and reopening would take too long and incur pointless costs.

Now all of this is pretty damning to the long termists. First of all, it means that long termists aren't actually long termists, they are short term thinkers of a different kind. I have seen "cute" animations on YouTube where people made the point that saving just a few seconds in the early stages will have a huge effect on the number of future humans. This isn't long term thinking, this is extreme short term thinking that you would expect when interest rates are really high. The fact that a lot of longtermists demand or are comfortable with extreme capitalism with high interest rates even when growth rates are low actually means that the short term is more important for them and they just use longtermism as a cover to care about their specific short term needs at the expense of other short term needs. Most commonly longtermists think rich countries are the only ones that matter and poor countries should be ignored. This is blatant short term thinking. The fact that they simply expect high growth rates to continue forever shows an obvious inability to think about the long term future. Growth at the expense of sustainability means lower total economic output of human society. If growth rates would ever go down or even fall to zero the whole long termism idea falls apart because there won't be 10^58 humans to gain utilitarianist superiority. Aging and shrinking populations are the longtermists worst nightmares even though a smaller population means sustainability is easier to achieve which should allow humanity to extend its lifespan instead of cutting it short because of ecological limits.

Second, an imposition of long term thinking by decree while ignoring obvious constraints to long term thinking in the monetary system is just going to put a bandaid on society without fixing the underlying problems. This leads to a perplexing contradiction. The purpose of the interest rate mechanism is to deal with short term needs, then near future needs and then progressively longer term needs. Longtermists just jump into the deep end of the future, not thousands, not hundreds of thousands of years, only time frames longer than millions of years matter.

Example: You are supposed to care about your two year old child going to college but not about feeding it because feeding it is going to take resources away from the capitalist that is growing the economy and population.

The reason why I heavily despise longtermism is that I have already found an economic system that allows people to quickly satisfy their short term needs which then frees up resources that can be allocated toward long term needs, in that order. Suspiciously, longtermism does not match the long term thinking that I am thinking of when I hear the phrase. When I hear longtermism the thought that crosses my mind is that these guys really hate the short term so much that it wraps back around and they end up comitting the short term thinking they pretend to despise.

Satisfying short term needs is a necessary prerequisite to satisfying long term needs, if you skip the most important short term needs then you are actually putting the long term future in jeopardy which is why excessive long term thinking ends up looking like short term thinking again.