This issue is not academic: works owned by the family continue to appear on the market.
He collected and owned works by many of his now famous customers.
The incident added fuel to a national debate over who owns works of public art.
Phillips bought not to compile a survey of 19th and 20th century art but to own works that moved him.
It also owns several smaller works by the artist.
Some people derive status from owning works of art.
But it said, "We can confirm that the facility contained works owned by a wide range of commercial galleries and individual collectors."
During that time, the total number of works owned by the museum has risen more than fourfold - from around 2,000 to around 8,500.
Philosophically intriguing are issues of who ultimately owns works of art.
But miniatures in books or muraqqa albums were private works owned by the elite.