Kimberly Dennis summarizes a cliché in such a way as to give me hope that maybe differing perspectives really are just a clarification away from harmonization (via Paul Caron, via Glenn Reynolds):

Successful entrepreneurs-turned-philanthropists typically say they feel a responsibility to “give back” to society. But “giving back” implies they have taken something. What, exactly, have they taken? Yes, they have amassed great sums of wealth. But that wealth is the reward they have earned for investing their time and talent in creating products and services that others value. They haven’t taken from society, but rather enriched us in ways that were previously unimaginable.

No. “Giving back” implies that they have received something that they did not create. Inasmuch as even the most rags-to-riches story is a far cry from an entrepreneur’s inventing the world from primordial muck, it is clearly true that the broader society has at the very least created the conditions in which his or her success was possible. That’s especially true for entrepreneurs, like Bill Gates, whose story is more of the riches-to-more-riches variety.
Glenn Reynolds brings into the conversation philanthropy’s sense of being Christian, but the point of Christian charity is not for the haves to make token gestures toward economic equilibrium. It’s to offer imitative thanks to the living God whom the giver is supposed to see in the recipient. The notion translates directly into secular terms as an expression of gratitude — and, one might say, debt — to a cultural and civic structure.
Business-minded libertarians, among whom Dennis appears to count, may respond to that call by advocating for freedom and donating to market-bolstering causes. Others may shoot for the more fundamental targets of diminishing starvation and disease. And still others see continued investment in their personal vocations — whether medicine, high-tech inventions, financial investment, or any other capitalistic venture — to be their most valuable possible contribution.
Insisting that this point be acknowledged does not indicate that one begrudges the success or dismisses the inventiveness of capitalism’s beneficiaries. But “giving back” isn’t (or shouldn’t be) penance in the form of an offering to the undeserving. It’s recognition that, even to the extent that luck was not decisive, community conditions might have been, and a freely expressed hope that those conditions can continue to benefit others who are deserving.