You can see the genius of Donald F. Sammis' idea. He knows, as we all do, that government assistance for the needy is inefficient. Certainly some of the tax-provided money, goods and services reach their targets, but an awful lot of money is eaten up in administrative overhead, the cost of running the bureacracy.

Sammis, a San Diego businessman, knows something else: Americans are a generous people. Tell them about a family whose home has been destroyed by fire, a child who can't go to school because he has no shoes, an elderly couple whose Thanksgiving dinner will consist of cold cuts, and the offers of shelter, clothing, shoes and food will be enough to bring a tear to the most cynical eye. The trouble is that this generosity is likely to produce more clothes, shoes and turkeys than the particular families could ever use while leaving other, less dramatic needs unattended.

But suppose, says Sammis, American generosity could be funneled through local organizations that know the need and also have the means of delivery. Sammis and an organization called Project Helping Hand have come up with a clever scheme called the Human Services Option (HSO) which he believes will make it possible. As Joseph Piccione describes the proposal in a monograph published by the Free Congress Research & Education Foundation, federal taxpayers would be allowed to earmark a certain portion of their income-tax liability--say 10 percent--for tax-exempt volunteer human services agencies.

"As the government has 'contracted out' human service work to private agencies in the past, under the HSO part of the funding for such work could originate in local areas--from individuals who choose current service programs or who, on a group or community basis, develop new programs to address specific local needs."

HSO's backers view it as neither a tax break nor a means of avoiding societal responsibility. The only break taxpayers would get is that they would be able to name the specific beneficiaries of their generosity. Any tax savings would result from increased efficiency.

Sammis offers an example of how HSO might work: a group of community residents wants a community center to help in the fight against teen-age gangs. "They form an association of 650 people who have a combined tax liability of $2,950,000. Their aggregate HSO (at 10 percent) would be $295,000--enough to make a substantial start on their community center."

The idea is appealing, not merely because it would get taxpayers directly involved in projects they consider especially worthy but also because many worthy programs are being curtailed as a result of the Reagan administration's budget cuts.

On the other hand, I've just read a New York Times reporter's account of the public reaction to a piece he did on a pre-Reagan administration cutback in public services. His story featured a blind man whose guide dog had its food allotment revoked and a ghetto mother of four forced by tightened welfare standards to give up her trainee's job and go back on the dole.

"I had to negotiate the checks for Shep and deliver a dog-food cornucopia that continued for months," wrote Francis X. Clines. "The finest and most humble of stationery carried confessions of tears shed for Shep . . . Generous checks were attached, some in excess of $100, even $200."

As for the destitute mother: "Nothing. A few letter writers, in staking Shep to a feed, complained about the public burden of the woman's irresponsible pregnancies . . . one even suggested that she be sterilized."