Fashion is by nature representative of something that has gone before it. Sometimes art, sometimes architecture, sometimes a celebrity with a penchant for baggy trousers. Fashion is reactive. And attempts at 'innovative' fashions invariably result in garments so terrible they cease being practical. The problem with 'retro' is that when some ingenious designer decides to re-do a particular decade, everyone else wants to get in on the act and before you know it the 1970s are back. Which brings us to the new spring arrivals from the French house of Dior. The decade plundered this season falls somewhere between the 40s and 50s, when women were tough, yet sexy and feminine. Inspiration for the shapely designs came straight from the Hollywood movie queens who reigned in that era. Greta Garbo's sharply-tailored trouser suits are perfect for a modern corporate gal on the way up. And when you mean business, Joan Crawford's power shoulder-pads are best for the boardroom. Dior does them in strong, bright colours, paired with knee-length straight skirts which impart a vitality and flair. Dior also can lay claim this season to having the perfect luncheon suit. Ladies-who-lunch should resist the temptation to buy the pastel-blue chenille number with the black bows and instead buy the grey peplum jacket that flares from the hip with a skin-tight, knee-hugging pencil suit. Another winner is the fitted skirt-suit in black and white houndstooth check, with a wee fitted jacket. It could have belonged to Lauren Bacall in any movie starring Humphrey Bogart. The only miss in the skirt-suit category is the laminated black cotton number with the white polka dots. Tough-talking dames do not steal the entire show. Graceful knit polo sweaters in black, edged with white and matching high-waist, wide-leg trousers, are reminiscent of Katharine Hepburn: clean and modern. Nobody does it better than Dior in evening wear. In formal gowns, the understated elegance with just the right amount of drama is outstanding. Show-stoppers came in the form of a figure-hugging, champagne-satin, floor-length portrait-collar ball gown and a spectacular silver-sequinned mermaid skirt offset to perfection by a simple black silk sleeveless shell.