How can we trace out the links between actions that people take today and really long-term outcomes for humanity - outcomes that stretch out indefinitely into the future? I call this effort macrostrategy - that is, to think about the really big strategic situation for having a positive impact on the long-term future. There's the butterfly effect: A small change in an initial condition could have arbitrarily large consequences.

For healthy adult people, the really big thing we can foresee are ways of intervening in the ageing process, either by slowing or reversing it.

The Internet is a big boon to academic research. Gone are the days spent in dusty library stacks digging for journal articles. Many articles are available free to the public in open-access journal or as preprints on the authors' website.

Knowledge about limitations of your data collection process affects what inferences you can draw from the data.

The cognitive functioning of a human brain depends on a delicate orchestration of many factors, especially during the critical stages of embryo development-and it is much more likely that this self-organizing structure, to be enhanced, needs to be carefully balanced, tuned, and cultivated rather than simply flooded with some extraneous potion.

When we are headed the wrong way, the last thing we need is progress.

Our approach to existential risks cannot be one of trial-and-error. There is no opportunity to learn from errors. The reactive approach - see what happens, limit damages, and learn from experience - is unworkable. Rather, we must take a proactive approach. This requires foresight to anticipate new types of threats and a willingness to take decisive preventive action and to bear the costs (moral and economic) of such actions.