The most uplifting and affirmative action I've seen this year occurred in distressing circumstances in Glasgow's Sauchiehall Street. The event was filmed by BBC Scotland for their series, The Street, chronicling the reality of life on Scotland's liveliest boulevard. In it we see Melo, a young African street musician, being racially abused by two white thugs. After one of the men approached him for the purposes of calling him a "black bastard", this is what we subsequently heard:

"What about the fucking British or the homeless? You are taking the fucking piss. You are milking our country for thousands, ya fucking black bastard.

"How much do you make sitting here busking every fucking day? You're making thousands. I pay taxes every fucking month; hundreds of pounds to keep you in the fucking country.

"You are a black bastard, admit it."

One of the white gargoyles then attempts to assault him. Melo, though, was having none of it and began rebuking his assailants while defending himself with a small trolley he had been using as a prop. Melo, who looks like a chap with substantial reserves of character and courage, decides he might as well go down fighting. "Get away from me," he tells them. "Any more and I will batter you both to the floor." It's thought that Melo had come to live in Glasgow after fleeing from the civil war in Angola, his home country.

For generations now, we Scots have congratulated ourselves that we don't have a racial problem on anything like the scale that exists in parts of England. It's a complacent attitude and one that has been blown apart since the start of this year. For there have been several other incidents reported in the press and television that have been as sickening as the attack on Melo. Two weeks ago a 17-year-old schoolboy making his debut in senior football had to be substituted when he became distressed at the abuse he was receiving from some supporters of Peterhead FC in the north east of Scotland.

On another occasion, Humza Yousaf, a young Asian MSP at Holyrood was subjected, in daylight, to a violent and racist tirade while selling the Big Issue. He had agreed to do this to raise awareness of issues surrounding homeless people in Scotland.

Few would suggest that these incidents mean that Scotland suddenly has a problem with racism. Yet we ought also to acknowledge that for each of these that were reported and recorded there will be dozens more that go unchronicled. Nor would it be wise to oversimplify the reasons why we are witnessing these bubbles on the surface of the cesspit. Yet it seems to me to be inescapable that some of these reasons are similar to those that we encounter when trying to explain the relatively sudden rise of a party like Ukip in Britain.

This is a party which, in the absence of any coherent economic, social or cultural policy, has become a significant power in England and Wales on the back of one of the most wicked deceptions ever practised on our southern neighbours: that immigration is intrinsically bad, that indolent people from "undesirable" countries (eastern Europe and most of Africa) are taking white Anglo-Saxon jobs, and that they are placing an unsustainable burden on the NHS and our system of benefits.

This has combined with a rise in anti-Muslim sentiment fuelled by tragic events such as the slaying of Private Lee Rigby. Rapidly, it seems, a residual fear and distrust of Islam, which had always lurked on the periphery of what we could call outright racism, has entered the mainstream. And it has done so as large elements of British society have begun to express themselves in distorted and strident militarism. In this, the humble poppy has also become a casualty. Once it was a silent and lovely memoriam to noble sacrifice, now it is used by our political and military elite to engender a sense of triumphalism. Not to be seen sporting a poppy in the month of November is to risk being accused of treason.

Much of this may be justified when Britain is facing mortal peril. But, in the absence of such, too many of us begin to look for an enemy within. Those who are other and different and puzzling become easy targets, especially those who are foolish enough to look content and prosperous. How dare they?

And now it seems that some of the tendrils of this creeping disease have reached Scotland. Well, we had better start to look aboot us, because these have the capacity to poison us. And we had better also start being loud and aggressive with the opposite message: Scotland needs more immigration. If we still think that old age deserves choice and quality of life then some facts must be faced. Britain has an ageing population and Scotland's is ageing more rapidly than that of the rest of the UK. We need another one million immigrants in this country paying taxes and national insurance as well as purchasing goods and services. This they tend to do and they tend not to get as sick and depressed as the rest of us. Happily, the SNP is the world's only nationalist party which actually welcomes immigration. The Scottish Labour party, when it governed, enshrined this, too.

It's good to walk down the streets of your city and behold the sights and sounds and smells of different people from far away countries. How can that ever be bad?

In England in the 16th century, in a time considered to be more inhumane and uncivilised, the words of William Shakespeare (from Sir Thomas More) resonate still:

"Imagine that you see the wretched strangers,

Their babies at the backs, and their poor luggage

Plodding to th' ports and coast for transportation[...]

Should so much come too short of your great trespass

As but to banish you: whither would you go?

What country, by the nature of your error,

Should give you harbour?[...]

Why you must needs be strangers. Would you be pleased

To find a nation of such barbarous temper

That breaking out into hideous violence

Would not afford you an abode on earth,

Whet their detested knives against your throats,

Spurn you like dogs[? ...]

[...] This is the strangers' case

And this your mountainish inhumanity."