What is capital? Capital is a thing (or service) that is produced not for consumption but for further production. The existence of capital industries implies several stages of production, or up to thousands upon thousands of steps in a long structure of production. Capital is the institution that gives rise to business-to-business trading, an extended workforce, firms, factories, ever more specialization, and generally the production of all kinds of things that by themselves cannot be useful in final consumption but rather are useful for the production of other things.
As Hayek emphasized in The Pure Theory of Capital, another defining mark of capital is that it is a nonpermanent resource that must nonetheless be maintained over time in order to provide a continuing stream of income. That means that the owner must be able to count on being able to hire workers, replace parts, provide for security, and generally maintain operations throughout an extended period of production.
Mr. Tucker might also have noted that capital is a red flag (literally!) to the covetous. There’s a lot of money there! Gimme some of it! For the CHILDREN (after suitable deductions for reasonable expenses, of course)! The real tragedy is that Sean Penn, who is “…actually living there, chugging up and down the hills of a shanty town, unshaven and disheveled, being what he calls a “functionary” and getting stuff for people who need it”, will never figure that out — or, if he should, would be cast out by his fellows as a pariah. There’s more than one Sean Penn out there.