First of all
The word herb is the noun from which herbaceous (in contrast to woody) comes. But we're talking about herbs and spices, here. Pronunciation is up to you—you may pronounce the "H" or not, as you choose. The word herb is borrowed from the French herbe (meaning grass), which accounts for the confusion over the pronunciation. One of my grandmothers said "(h)erbs and spices," the other said "herbs and spices," and both were correct.
Some herbs are just herbs
Basil, for instance, fits perfectly into dictionary.com's second definition of an herb. It's a leafy plant valued for its aromatic foliage, flavor or medicinal properties. (I'm not aware of any medicinal properties currently attributed to basil, but it contributes mightily to the wonderful feeling of a full tummy after a meal of pesto and pasta!) The seeds of basil are only used for producing next year's crop of this delicious annual herb.
Spices that aren't herbs
Most of the spices we tend to think of as strictly spices are roots (tumeric), seeds (peppercorns, cardomom), or other, non-leafy parts of the plant, like bark (cinnamon) or flowers (cloves)
If you believe that herbs are leaves like rosemary leaves, and spices are seeds like poppy seeds or roots like ginger root, then something like dill will tie you in knots (maybe for a knot garden). The leaves of the dill plant are delicious in salads, with fish, and in dips, but when they flower, the dill seeds are harvested for use in dill pickles and other spicy recipes. Similarly, cilantro is eaten as a tender young leaf in salads and in salsa, but the seeds of the plant are known as coriander and are used on their own or in curries.
It takes all kinds
Some herbs, like cumin or calendula, are annual herbaceous plants that have to be replanted every year. Others, like sage or thyme are perennial. Parsley and its close cousins are apparently biennial, but most are enjoyed for their foliage and replanted each year. Bay laurel, or sweet bay, from which we get bay leaves, is a woody tree growing in Mediterranean-type climates. Some herbs like it rich and moist, others like it lean and dry. There really can be no generalization, as herbs come from so many different parts of the world.
Religious uses for herbs and spices
Famously, the three Magi who visited the infant Jesus brought rare and expensive spices: frankincense and myrrh, both used in religious ceremonies and each derived from tree resins. Other herbs are prized for their aromatic value and are used as components of incense in Catholic and other Orthodox Christian religious ceremonies as well as in Native American, Shinto, Buddhist, and Jewish religious practices. They are certainly mentioned frequently in the Jewish, Chistian and Muslim holy texts. Herbs were probably also sacred to long-lost cultures of ancient Egypt, the Incas, Babylon and all over the ancient world.
Medicinal uses for herbs and spices
Cave drawings in France dated to as long as 27,000 years ago show people using plants medicinally. Sumer, the culture that produced cuneiform writing and is credited with the invention of the wheel, cultivated herbs along with wheat, barley and sheep, maybe as long as 6,000 years ago!
Traditional Chinese medicine, experts estimate, has been using herbs to heal and promote health for nearly 5,000 years, although the first printed guide to herbs was in the year 265, more or less. (Scholars disagree.) TCM relies heavily on herbs, some familiar to us (licorice root), some strangely exotic (Four Gentleman TeaPills). In India, Ayurvedic medicine using herbs was practiced as long as 5,000 years ago. The "Iceman," discovered in the Alps in 1991 and believed to be some 5,300 years old, carried a bag of medicinal herbs.
Five centuries before the birth of Jesus, a Greek philosopher and healer named Hippocrates had the novel idea that diseases were not caused by sins or gods but by agents outside the body. Another, later Greek text, Latinized as De Materia Medica, written a few generations after Jesus, was translated into Latin and Arabic and remained widely translated and copied throughout the next thousand years. De Materia Medica was used as an herbal guide both in European and in Eastern medicines—Arabic, Indian, Tibetan and Chinese. Below to the right, is pictured a page in Arabic, illustrating medicinal uses of cumin and dill, and dating from 1334 (while the Western world was still struggling through the Middle Ages)!
DE MATERIA MEDICA translated into Arabic, with illustrations of cumin and dill, from approximately 1334
Herbs are used traditionally in every human culture, not just the ones I mention here. It is clear that the ancient peoples of the world have been using herbs for a long, long, long time! Herbs are here to stay, and that's good. So the uses of herbs and spices for seasoning, in religious ceremonies and to promote healing is thousands and thousands of years old and from many, many cultures around the world.
There are a number of wonderful articles here on the DavesGarden.com site that cover many aspects of herbal medicine, and a number of off-site links are provided below. As always, please consult your own doctor before treating anything serious with herbal medicine.
Dave's Gardensubscribers can participate in the Herbs Forum!
A Cherokee Look at Herbs and Plants by Mitch Fitzgerald
Sharon Brown's articles almost all have some aspect of an herbal remedy or herbal history in them
Herbal Remedies for Cold and Flu Symptoms by Bev Walker - Bev also writes about growing and using herbs
Growing Herbs Indoors by Karen Jones - Karen also has other articles about using herbs for home products
Index of Culinary Herbs and Spices from FoodandNutrition.com
Photo credit: a big thank you to DG subscriber rosemarythyme. All other images are in the public domain.