The court was told Mr Boyce, bottom right, would not have put his record at risk by getting involved in a conspiracy to extort £4.25m
A court has been told a solicitor would not have put his unblemished record at risk by getting involved in a plot to ransom a stolen Leonardo da Vinci.
In his closing speech, defence QC David Burns said David Boyce, 63, should be cleared of a conspiracy charge.
He said claiming his client could have got involved amounted to a "startling proposition".
Mr Boyce is one of five men who deny conspiring to extort £4.25m to bring back the Madonna of the Yarnwinder.
The painting was stolen from the Duke of Buccleuch's Drumlanrig Castle in Dumfries and Galloway in 2003.
Mr Burns told the High Court in Edinburgh his client believed everything he had done was legal and above board.
He added he would do nothing to harm his staff or his own standing.
The lawyer denied that Mr Boyce had become part of a criminal conspiracy.
"Application of your commonsense may tell you that this is wholly incredible," he said.
"Would he risk ruin, his career, his future by becoming knowingly involved in a plan to extort?"
The court has previously heard from QC Jack Davidson, representing Mr Boyce's former colleague Calum Jones.
He described the case as "a colourful tale" but insisted his client had done no wrong.
Mr Davidson said it beggared belief that during the course of a meeting lasting little over an hour Mr Jones had agreed to a career-wrecking conspiracy plan, putting his whole life in jeopardy, with people he had never met before.
On trial with Mr Boyce, of Lanarkshire, and Mr Jones, 45, of Renfrewshire, are Robert Graham, 57, Marshall Ronald, 53, and John Doyle, 61, all from Lancashire.
They deny conspiring to extort £4.25m between July and October 2007. The trial continues.