Let me start with a disclaimer: Judge Brian Mashile is my brother and I have known former finance minister Trevor Manuel since the days of the United Democratic Front as a fellow activist in the 1980s. I hold both men in high esteem.

Mashile is a humble and dispassionate person, a stickler for fairness, logic and rationality and, above all, a conscientious jurist.

His rise from the bottom rung of apartheid's socially constructed ladder as a black and visually impaired person to the bench speaks volumes of the tenacity of the human spirit and the nobility of the anti-apartheid Struggle's exhortation for the recognition and affirmation of the talent of all our people, black and white.

Manuel is a renowned activist. His consciousness spurred him to battle against apartheid and, as minister, he shamed the stereotype of black incompetence after succeeding Chris Liebenberg as finance minister in April 1996.

He presided over National Treasury with professionalism and frugality, which enabled the country to fund the avalanche of post-1994 policies and cushioned SA from the ravages of the 2008 sub-prime financial crisis, among many successes.

But Manuel's snide remark last week about a "single individual who happens to wear a robe" directed at Mashile's judgment in the matter between insurance and banking group Old Mutual and its chief executive Peter Moyo will probably go down as his most unfortunate lapse of judgement in a long and illustrious political métier and promising business career.

It was untidy; in poor taste. Manuel allowed anger to get the better of him. In the process, he sullied and caricatured not just one judge but the entire judiciary at a time when this important branch of government regularly comes under the most virulent and vulgar attacks from immodest and suspicious quarters of society.

Like all human beings, judges are not beyond reproach; Mashile is no exception. It may come to pass that his judgment in the Old Mutual versus Moyo matter may later be overturned by a superior court.

Additionally, the judiciary is strengthened rather than weakened by critical engagement with its findings.

Indeed, if the law is to serve the people as it should, and avoid the contempt of Mr Bumble's kind - "the law is an ass, an idiot" - as in Charles Dickens's Oliver Twist, judges must be open to honest and constructive criticism.

Irresponsible appraisals of the judiciary on the other hand do not only lower its image and standing in society; they lay the basis for some to consider taking the law into their own hands as an option because the pejoratives suggest that judges - and possibly other areas of the criminal justice system - are illegitimate and incapable of meting out justice in a fair, objective and impartial manner.

They also do not advance society's appreciation and understanding of the workings of the judicial system. They de-educate, further polarise society and keep alive perspectives that may have been apposite at a different period of history but which no longer hold true.

Manuel's "single individual who happens to wear a robe" remark sadly belongs to this category of impulsive and irresponsible talk. He, of all people, ought to know better, that conduct such as he engaged in last week lends credence to a growing and dangerous tendency which, together with others, pose a threat toour democracy as a going concern.

Society is in greater danger when respectable political and business leaders like Manuel enter the scene in a manner that fuels irresponsibility in public discourse. It makes it that much harder to address the problems whose resolution require circumspection, consideration and judiciousness.

Hopefully, Manuel will take steps to make amends not so much to the person of Judge Mashile as in to repair the damage caused to our understanding of the role and place of the judiciary in our constitutional order.

*Mashile-Nkosi is executive chairperson of Kalagadi Manganese, a mining company in Johannesburg