Chris Grayling told peers today that it is a 'positive benefit' that the lord chancellor is a non-lawyer.
Grayling, who is the first non-lawyer to be in the post for 440 years, appeared before the House of Lords constitution committee, which is holding an inquiry into the role.
The Epsom MP was grilled for more than an hour on the constitutional role and whether his position as justice secretary caused a conflict in his commitment to the rule of law.
Grayling told committee members that it was an advantage for a non-lawyer to be lord chancellor - particularly at a time when legal aid cuts have to be made.
'I don't think that the person holding my job suffers from not being a lawyer,' he said. 'We don't need a health secretary who is a doctor. I don't believe you need to be a practising lawyer and understand the minutiae of the court to protect the values of our justice system.'
He added that a non-lawyer could take a 'dispassionate' approach to reforms and that these may not be well received by the legal profession.
He also rejected as 'misplaced' the idea that a lawyer would have chosen to retain legal aid as it was before the Legal Aid, Sentencing and Punishment of Offenders Act 2012, pointing to cuts made by his predecessor, Kenneth Clarke QC.
'Perhaps there's a belief that a separate lord chancellor would take different decisions on legal aid. That's simply not the case,' he added.
Grayling, who said it would be a 'big mistake' to separate the roles of justice secretary and lord chancellor, revealed he had admonished one fellow minister in his time in office for public criticism of a judge.
He also stated he was 'not comfortable' with a senior judiciary dominated by men but insisted it was not right to artificially promote people before they are ready for the role simply because they are women.
Grayling said he was 'satisfied' with the legal advice available to him despite three recent defeats in the High Court on judicial reviews. 'Sometime we are right and sometimes we are wrong - we are only human.'
But he defended his plans for reform of judicial review as 'necessary, proportionate and dealing with an area that's not working very well'. He says this is a matter for parliament and it would be a mistake to invite judges to comment.
In response to Grayling's evidence, Bar Council chair Nicholas Lavender said the lord chancellor should be a 'champion' of the justice system as well as guardian of the constitution.
'He is entrusted with lead responsibility in government to maintain the delicate balance between, on the one hand, upholding the rule of law and protecting the independence of the judiciary and, on the other hand, respecting the interests of the executive.
'Legal expertise is essential to fulfil such a unique role. The lord chancellor should be a very senior lawyer.'