"One of your tasks is to separate the "personal" from the "substantive." The two can become confused, especially if someone rubs the President wrong"

This quote by Donald Rumsfeld is referring to the significance of distinguishing between individual sensations and the real substance of a scenario. It is essential to be able to separate the two, specifically when handling the President, as it can be simple to let personal feelings cloud judgement. It is important to be able to look at a circumstance objectively and make decisions based on the facts and not on any individual sensations. This is specifically real when dealing with the President, as it is necessary to be able to make choices that remain in the best interest of the country, not just the President. It is very important to be able to separate the individual from the substantive in order to make the very best decisions possible.